Process for Preparing Torrefied Biomass Material Using a Combustible Liquid

ABSTRACT

A process for preparing torrefied densified biomass and/or torrefied densified biosolids comprising about 2% to about 25% w/w combustible liquid is disclosed. The process involves densifying biomass and/or biosolids, or providing a densified biomass and/or densified biosolids, and submerging the densified material in a hot combustible liquid for about 2 to about 120 minutes until the densified material is torrefied. The combustible liquid may be derived from any source exemplified by an oil such as those derived from plant, marine and animal sources, or alternatively, a petroleum product. The combustible liquid is heated to a temperature in the range of about 160° C. to about 320° C. prior to submersion of the densified biomass material. Also disclosed is a biomass torrefied densified biomass and/or torrefied densified biosolid comprising about 2% to about 25% w/w combustible liquid.

TECHNICAL FIELD

The present disclosure pertains to torrefied biomass and/or biosolids,and in particular, to a torrefied densified biomass and/or torrefieddensified biosolid comprising a combustible liquid and processes forpreparing such torrefied densified biomass and/or biosolids using acombustible liquid.

BACKGROUND

Biomass and biosolids are becoming important sources of energy as thesupply of fossil fuels decreases. Burning of petroleum, coal and otherfossil fuels also leads to pollutants and greenhouse gases beingreleased into the air and water. Biomass and biosolids are renewable,produce significantly fewer greenhouse gases than fossil fuels and arewidely available. Raw biomass and biosolids, however, generally have alow density resulting in inefficient storage and transportation. The lowenergy densities and higher moisture contents of raw biomass andbiosolids also hampers the widespread use of raw biomass and biosolidsas a source of thermal energy or as a coal replacement.

Torrefaction of raw biomass and biosolids has been developed recently toturn the biomass and biosolids into a charcoal-like state byslow-heating the biomass and biosolids in an oxygen-free or low-oxygenenvironment to a maximum temperature of about 300° C. The lack of oxygenprevents the biomass and/or biosolids from burning, and instead, thematerial is torrefied. Slow-heating biomass and biosolids also leads toloss of mass due to the volatile organic compounds (VOCs) within the rawbiomass and biosolids being gassified. Torrefaction also causes chemicalchanges to the cellular structures of the material, resulting in apartial loss of mass and a loss in mechanical strength and elasticity.Torrefaction, therefore, also produces a product that has increasedfriability and grindability. Furthermore, torrefied material ishydrophobic and therefore, stays dry and is insensitive to atmospherichumidity. This reduces the risk of rotting, overheating, andauto-ignition of the materials when stored.

Prior art torrefaction processes generally involve one of high-pressuresteam, high temperature inert gas or superheated steam in the heattreatment processes. Other torrefaction processes using gas or pressureor vacuum methods may also be used. Most of these prior technologies,however, fail to efficiently and practically convert biomass intotorrefied wood in a simple, easy, quick, practical, safe, uniform andeconomic way. In particular, using any type of inert gas or steaminvolves large containment systems with large amounts of surface area,high equipment costs, high energy costs, slow treatment rates, and lowoverall operating efficiencies with resultant high production costs. Thesystems and equipment are complex and large for containing the inert gasor steam heat transfer medium, and often require heavyweight materialsgiven the high operating pressures required with steam. Furthermore,these systems often require more than an hour to torrefy biomass.Consequently, the prior technologies also have challenges withscalability.

Recent torrefaction processes have also used bio-liquids (such as,vegetable oils, soybean oils, canola oils or animal tallow), paraffinichydrocarbons, oil, molten salts or paraffin, to heat and torrefybiomass. Some of these technologies, however, involve intricatelydesigned housings for holding the liquids and torrefying the biomass,and require the biomass to pass through a plurality of pools, rivers orliquid compartments holding the liquids during the torrefaction process.These processes, therefore, may require additional engineering efforts,complicated designs and large volumes of the torrefying liquids.Moreover, these processes often involve a pre-heating stage and/or adrying stage prior to the torrefaction treatment, thus, being costly tooperate and time-consuming.

SUMMARY

The exemplary embodiments of the present disclosure generally pertain toa torrefied densified biomass and/or biosolid comprising a combustibleliquid and processes for preparing the torrefied densified biomassand/or biosolid using a combustible liquid exemplified by hydrocarbons,such as plant-derived oils, marine-derived oils, animal-derived oils,petroleum products and bitumen-based products.

An exemplary process for preparing a torrefied densified biomass and/ortorrefied densified biosolids of the present disclosure is disclosedherein, in which a combustible liquid is used for torrefying a densifiedbiomass material and/or densified biosolid material. The exemplaryprocess may comprise one of two starting materials: (i) the initialstarting material may be raw biomass and/or biosolids that undergodensification prior to heating in the combustible liquid; or (ii) theinitial starting material may be densified biomass and/or densifiedbiosolids that are readily available in the marketplace.

An exemplary process of the present disclosure generally comprises thesteps of densifying raw biomass and/or biosolids; submerging thedensified material into a combustible liquid heated to a temperature ina range of about 160° C. to about 320° C.; and torrefying the densifiedmaterial in the heated combustible liquid for about 2 minutes to about120 minutes to produce a torrefied densified biomass and/or biosolid.The resulting torrefied densified material comprises about 2% to about25% w/w combustible liquid. The densified biomass and/or biosolids maybe directly transferred from the densifying process into the combustibleliquid to minimize any loss of heat gained by the biomass/biosolidsdensification. This may increase efficiency of the process as the heateddensified biomass and/or densified biosolids will require less heatingin the combustible liquid.

The process may further comprise a drying step post-densification orprior to transferring the densified material into the combustibleliquid. Drying may be done in conjunction with densification.

The starting feedstock may also comprise commercially availabledensified biomass and/or densified biosolids. With such feedstocks, theinitial densification step disclosed herein is not required.

The biomass material to be torrefied may comprise any type of materialderived from living or recently living organisms, and are exemplified byplant biomass such as sugar-cane bagasse, corn stover, rice straw, wheatstraw, bamboo, switchgrass, and hemp. The biomass material may alsocomprise wood biomass such as softwood, hardwood, sawdust, hog fuel andwood byproducts. The biosolids may be recovered from sewage orwastewater during a sewage treatment process, alternatively obtainedfrom municipal sewage treatment processes, alternatively obtained fromindustrial waste streams exemplified by fruit and vegetable processingplants and fibre processing plants, or alternatively, may beagricultural wastes from livestock and poultry production. The biomassand/or biosolids may also be any combination of the feedstocks describedherein.

The exemplary processes disclosed herein may also be continuousprocesses, semi-continuous processes, or batch processes. In suchprocesses, the supply of biomass material to a pelleter or briquettermay be continuous or semi-continuous or in batches. Alternatively, ifcommercially available densified biomass and/or densified biosolids areused, then the supply of such densified material to the combustibleliquid may be continuous or semi-continuous or in batches.

The combustible liquid preferably comprises a hydrocarbon exemplified byplant-derived oils, marine-derived oils, animal-derived oils, petroleumproducts and bitumen-based products that are heatable to a temperatureof up to about 320° C. The combustible liquid may be derived from anysource such as, for example, an oil derived from a plant source, amarine source, an animal source, a petroleum product and a bitumen-basedproduct. For example, the combustible liquid may be canola oil, linseedoil, sunflower oil, safflower oil, corn oil, peanut oil, palm oil,soybean oil, rapeseed oil, cottonseed oil, palm kernel oil, coconut oil,sesame seed oil, olive oil, animal tallow, fish oil, liver oil, andmixtures thereof. Alternatively, the combustible liquid may be apetroleum-based oil or a bitumen-based oil, such as, for example, asynthetic motor oil or engine oil exemplified by 5W-30 and 10W-30 engineoil; a chainsaw bar oil; a chain oil; transmission fluid oils and fluidsexemplified by automatic transmission fluids (ATF); hydraulic fluids;gear oils; diesel fuel; paraffin wax; paraffin oil; kerosene, stove oil;and mixtures thereof

The torrefied densified biomass and/or biosolid disclosed herein andobtained from the processes described herein may absorb between about 2%and 25% w/w combustible liquid during the torrefaction process, and mayhave a heat energy value of about 6,000 BTU per pound on a bone drybasis to about 13,000 BTU per pound on a bone dry basis, or any amounttherebetween. The heat energy value may also be expressed in gigajoulesper metric tonne (GJ/t), with the torrefied densified biomass and/orbiosolid obtained from the processes described herein having a heatenergy value of about 22 GJ/t on a bone dry basis to about 27 GJ/t on abone dry basis, or any amount therebetween.

The torrefied densified biomass and/or biosolid disclosed herein andobtained from the processes described herein may also comprise a carboncontent of about 50 carbon % on a bone dry basis to about 65 carbon % ona bone dry basis and may also be hydrophobic in nature.

The exemplary processes disclosed herein may also include a gascollection and condenser system for collecting and separating VOCs,vapours and steam expelled and/or generated during the densification,drying and torrefaction processes, for condensation and separation intoreusable energy sources.

DESCRIPTION OF THE DRAWINGS

The present disclosure will be described in conjunction with referenceto the following drawings in which:

FIG. 1 is a schematic flowchart showing an exemplary process forpreparing a torrefied densified biomass material and/or a torrefieddensified biosolid material;

FIG. 2 is schematic flowchart showing a second exemplary process forpreparing a torrefied densified biomass material and/or a torrefieddensified biosolid material;

FIG. 3 is a schematic flowchart showing an exemplary process fordensification and torrefaction of a biomass feedstock;

FIG. 4 is a schematic flowchart showing an exemplary process fordensification and torrefaction of a hog fuel feedstock;

FIG. 5(A) is a perspective top-side view of an exemplary embodiment of atorrefusion reactor for use in a continuous, semi-continuous or batchthroughput torrefaction process of the present disclosure, showingtorrefied pellets being transported out of a combustible liquid; FIG.5(B) is a perspective top-side view of an exemplary alternativeembodiment of a torrefusion reactor for use in a continuous,semi-continuous or batch throughput torrefaction process of the presentdisclosure, with densified biomass and/or densified biosolids beingloaded in a densified biomass/biosolids metering bin;

FIG. 6(A) is a perspective top-side view of the torrefusion reactorshown in FIG. 5(B), showing torrefied pellets being transported out of acombustible liquid; and FIG. 6(B) is a perspective top-side view of thetorrefusion reactor shown in FIG. 5(B), showing the direction ofrotation of the conveyor of the torrefusion reactor as densified biomassand/or densified biosolids proceed through the continuous,semi-continuous or batch throughput torrefaction process of the presentdisclosure;

FIG. 7 is a chart showing physicochemical changes that occur in abiomass feedstock over a period of time during processing with anexemplary torrefaction process disclosed herein;

FIG. 8 is a graph showing the heat value of biomass feedstock that hasbeen processed with an exemplary torrefaction process disclosed herein,wherein the biomass feedstock has been processed at differenttemperatures for different periods of time;

FIG. 9 is a graph showing the heat value of biomass feedstock that hasbeen processed with an exemplary torrefaction process disclosed herein,wherein the biomass feedstock has been processed at differenttemperatures for different periods of time;

FIG. 10 is a graph showing the carbon content of a biomass feedstockthat has been processed with an exemplary torrefaction process disclosedherein, wherein the biomass feedstock has been processed at differenttemperatures for different periods of time;

FIG. 11 is a graph showing the mass of biomass feedstock and the oilabsorption by biomass feedstock that has been processed for differenttime periods using canola oil as the combustible liquid;

FIG. 12 is a graph showing the mass of biomass feedstock and the oilabsorption by biomass feedstock that has been processed for differenttime periods using paraffin wax as the combustible liquid;

FIG. 13 is a graph showing a comparison between the total losses ofcombustible liquids canola oil and paraffin wax in an exemplarytorrefaction process according to the present disclosure;

FIG. 14 is a graph showing a comparison between the reductions in weightof biomass feedstock (in %) when canola oil or paraffin wax are used asthe combustible liquids in an exemplary torrefaction process accordingto the present disclosure;

FIG. 15 is a graph showing comparisons of water absorption by biomassfeedstocks that have been processed at different temperatures fordifferent periods of time in an exemplary torrefaction process accordingto the present disclosure;

FIG. 16 is a graph showing comparisons of water absorption by biomassfeedstocks that have been processed for increasing time periods and atincreasing time periods with an exemplary torrefaction process of thepresent disclosure;

FIG. 17 is a graph showing total oil absorptions by biomass feedstockprocessed with different types of oil as combustible liquids with anexemplary torrefaction process of the present disclosure;

FIG. 18 is a graph showing total oil absorptions by biomass feedstockprocessed with different types of oil as combustible liquids with anexemplary torrefaction process of the present disclosure; and

FIG. 19 is a perspective side view of a small-scale torrefusion reactorsuitable for use in some of the exemplary torrefaction processesdisclosed herein.

DETAILED DESCRIPTION

The exemplary embodiments of the present disclosure pertain to torrefieddensified biomass and/or torrefied densified biosolids comprising acombustible liquid exemplified by hydrocarbons. Some exemplaryembodiments pertain to processes for preparing a torrefied densifiedbiomass and/or torrefied densified biosolids comprising a combustibleliquid. Suitable combustible liquids are exemplified by plant-derivedoils, marine-derived oils, animal-derived oils, petroleum-based productsand bitumen-based products.

The exemplary torrefaction processes disclosed herein require a reducedenergy consumption as compared to prior art processes, while improvingprocess efficiency and feedstock throughput. Energy exemplified by VOCsand steam, produced during the process, may be recycled through thesystem to heat the combustible liquid, and/or to create pellets fortorrefaction, and/or to torrefy the densified biomass. It wassurprisingly found that minimal oil is actually absorbed by thedensified biomass during the present torrefaction processes.Accordingly, the combustible liquids used during the torrefaction stepsmay be repeatedly recycled and reused to process additional biomassfeedstocks, thus reducing input costs. Furthermore, any type of oil maybe used for these processes, including less valuable and cheaper oilsthat may have high contents of unsaturated fats, thereby even furtherreducing input costs. It is to be noted that use of a densified materialas a biomass feedstock will reduce torrefaction processing time, asdemonstrated in the Examples provided herein.

The torrefaction processes disclosed herein also do not require a vastamount of space to operate and are easily assembled and used, especiallygiven that the various steps of the process do not need to occur withina wholly connected system. The dryer, densifier, receiving container fortorrefaction, and cooling system may all be stored separately and set upin independent locations.

Moreover, the torrefaction processes disclosed herein provide animproved quality of torrefied densified biomass as the residual oil onthe surface of the torrefied densified biomass reduces the amount ofdust and other combustible materials on the biomass' surface. Thetorrefied densified biomass produced by the exemplary processes istherefore hydrophobic. Accordingly, the exemplary processes produce atorrefied densified product that is easily transportable and shippableas it does not create an explosion hazard. The torrefied densifiedproduct can readily be used as a biofuel.

Suitable biomass feedstocks for exemplary processes and productsdisclosed herein include harvested plant materials exemplified byhardwood trees and softwood trees which may have been processed intochips and/or sawdust and/or pellets, including briquettes, and/or debrisand wood waste from wood-processing operations, fibrous annual orperennial crops such as Salix, switchgrass, corn stover, straws producedfrom harvesting of cereals and/or oilseed crops; or material obtainedfrom waste streams produced from fruit processing plants or vegetableprocessing plants or cereals processing plants or oilseeds processingplants, or obtained from bagasse from sugar cane. Also suitable arebiosolids materials. As used herein, “biosolids” means any solid orsemisolid organic material recovered from sewage or wastewater during asewage treatment process, obtained from municipal sewage treatmentprocesses, or alternatively, may be agricultural wastes from livestockand poultry production.

The use of biomass materials has been limited as biomass generally has alower energy content and lower energy density compared to traditionalfossil fuels. The present disclosure pertains to a densified orpelletized biomass material, including biomass densified intobriquettes, as the starting material for torrefaction to increase thestarting energy of the raw biomass material (for example, pelletized orotherwise densified biomass, such as briquettes, on a dry basis, canhave an energy value of up to 40 lbs/cu ft, as compared to 8 lbs/cu ftfor loose biomass material). As understood in the art, densification isa process for increasing the density of the biomass, and many forms ofdensified biomass are readily available, such as wood pellets andbriquettes. Moreover, various procedures for densifying biomass areknown in the art and may be employed in the present process, such as,but not limited to, extrusion, briquetting, pelleting and agglomeration.

The term “densified” as used herein means a biomass material that hasbeen compressed to increase its density. The densified biomass materialwill be understood to be various shaped modules of biomass, with theindividual pieces having uniform shapes or non-non-uniform shapes.

The term “pelletized” as used herein means a biomass material that hasbeen compacted or concentrated into pellets, or pressed into briquettes.The pellets may be of any shape such as those exemplified by cubes,pellets, pucks, briquettes, and synthetic logs, wherein the individualpieces have uniform shapes or non-non-uniform shapes. The briquettes mayalso be of any shape such as exemplified by squares, rectangles,triangles, quadrilaterals, or any regular polygon (such as, for example,pentagons, heptagons, octagons and the like) or alternatively irregularpolygons. The individual pieces may have uniform shapes or non-uniformshapes, asymmetric shapes or symmetric shapes.

Hereinafter, the term “densified” shall refer to densified andpelletized materials collectively, including, without limitation,pellets and briquettes, which retain some moisture content, such as, forexample, an initial moisture content in the densified biomass and/orbiosolids material of at least about 1%. The densified biomass and/orbiosolids material may also have an initial moisture content of at leastabout 1.5%, at least about 2%, at least about 2.5%, at least about 3%,at least about 3.5%, at least about 4%, at least about 4.5%, at leastabout 5%, at least about 5.5%, at least about 6%, at least about 6.5%,at least about 7%, at least about 7.5%, at least about 8%, at leastabout 8.5%, at least about 9%, at least about 9.5%, at least about 10%,at least about 11%, at least about 12%, at least about 13%, at leastabout 14%, at least about 15%, at least about 16%, at least about 17%,at least about 18%, at least about 19%, at least about 20%, or anymoisture content therebetween.

The term “densification” used herein shall refer to densification,pelletization and briquetting processes. Furthermore, the densifiedbiomass material may also be referred to as “pellets,” “cubes” or“briquettes” herein. However, it should be understood that the densifiedbiomass referred to herein does not include charcoal briquettes whichare already torrefied and therefore cannot be torrefied any further.

As used herein, the term “wet basis” or “As Received Basis” refers toactual values or chemical measurements of a sample of densified biomassmaterial or a sample of torrefied densified biomass, as obtained from ananalysis of the sample, and includes, without limitation, moisturecontent, % ash, % volatile matter, % fixed carbon, % sulphur, % carbon,% nitrogen, % oxygen, and calorific values, such as heat energy valuesin Btu/lb, GJ/t, Kcal/kg.

As used herein, the term “dry basis” refers to theoretical values thatare calculated from the “wet basis” or “as received basis” values toprovide results for a sample of densified biomass material or a sampleof torrefied densified biomass as if there was no moisture in the sample(i.e., if it was bone dry; total heat value as though dry). Accordingly,as used herein, the term “bone dry basis” refers to the theoreticalvalue for a sample of densified biomass material or a sample oftorrefied densified biomass with zero detectable moisture content.

The torrefaction processes of the present disclosure generally pertainto immersion of densified biomass material into a combustible liquidmaintained at a temperature in the range of about 160° C. to about 320C, for a period of time in the range of about 2 minutes to about 120minutes, for about 5 minutes to about 120 minutes, for about 8 minutesto about 90 minutes, for about 10 minutes to about 60 minutes, for about12 minutes to about 45 minutes, or for about 15 minutes to about 30minutes.

As used herein, the term “combustible liquid” means the liquid forcontacting and immersing therein the densified biomass material, andthen torrefying the densified biomass material in the combustibleliquid. The term “combustible liquid” may comprise a hydrocarbon-basedoil exemplified by plant-derived oils, marine-derived oils,animal-derived oils, petroleum products and bitumen-based products, andmay also comprise a synthetic fuel or a synthetic oil. Suitableplant-derived oils are exemplified by canola oil, linseed oil, sunfloweroil, safflower oil, corn oil, peanut oil, palm oil, soybean oil,rapeseed oil, cottonseed oil, palm kernel oil, coconut oil, sesame seedoil, olive oil, and mixtures of plant-derived oils. Suitableanimal-derived oils are exemplified by animal tallow, fryer greases, andliver oil among others, and mixtures thereof. Suitable marine-derivedoils are exemplified by whale oil, seal oil, fish oil, algal oils, andmixtures of marine-derived oils. Suitable petroleum products areexemplified by synthetic motor oil and engine oils such as exemplifiedby 5W-30 and 10W-30 engine oils, chainsaw bar oil, chain oil,transmission fluid oils and fluids such as automatic transmission fluids(ATF), hydraulic fluids, gear oils, diesel fuel, paraffin wax, paraffinoil, kerosene, and stove oil, among others, and mixtures thereof. Asuitable synthetic fuel or synthetic oil may be produced by a FischerTropsch conversion process and is exemplified by pyrolysis oil and thelike. The combustible liquid may also be any combinations ofplant-derived oils, marine-derived oils, animal-derived oils, petroleumproducts and synthetic fuels or oils. The combustible liquid used in thepresent disclosure may further be heatable to a temperature of up to320° C. As used herein, the combustible liquid is for heating densifiedbiomass material in an oxygen-free environment to torrefy the densifiedmaterial without igniting it, rather than for the infusion of densifiedbiomass material with the combustible liquid or alternatively, forcausing a significant increase in absorption of combustible liquid bydensified biomass material.

The products of the torrefaction processes disclosed herein aretorrefied/densified biomass and/or biosolids material that retain aportion of the combustible liquid and have a high degree ofhydrophobicity. The torrefied densified biomass and/or biosolid obtainedfrom the processes described herein may absorb between about 2% andabout 25% w/w combustible liquid during the torrefaction process, or anyamount therebetween. For example, without limitation, the amount ofcombustible liquid absorbed and retained within torrefied densifiedbiomass may be about 2% to about 25% w/w combustible liquid, or anyamount therebetween; about 2% to about 24% w/w combustible liquid, orany amount therebetween; about 2% to about 23% w/w combustible liquid,or any amount therebetween; about 2% to about 22% w/w combustibleliquid, or any amount therebetween; about 2% to about 21% w/wcombustible liquid, or any amount therebetween; about 2% to about 20%w/w combustible liquid, or any amount therebetween; about 2% to about19% w/w combustible liquid, or any amount therebetween; about 2% toabout 18% w/w combustible liquid, or any amount therebetween; about 2%to about 17% w/w combustible liquid, or any amount therebetween; suchas, for example, 3% w/w combustible liquid, 4% w/w combustible liquid,5% w/w combustible liquid, 6% w/w combustible liquid, 7% w/w combustibleliquid, 8% w/w combustible liquid, 9% w/w combustible liquid, 10% w/wcombustible liquid, 11% w/w combustible liquid, 12% w/w combustibleliquid, 13% w/w combustible liquid, 14% w/w combustible liquid, 15% w/wcombustible liquid, 16% w/w combustible liquid, or any amounttherebetween.

Those skilled in the art would understand that the biomass and/orbiosolid materials of the present disclosure have a range of heat energyvalues. Those skilled in the art would know that exemplary energy valuesof the densified biomass and/or biosolids may range from about 4,300 BTUper pound to about 12,800 BTU per pound, depending on the feedstock andthe moisture content of the feedstock. For example, a skilled person inthe art would known that wood generally has an energy content of about6,400 BTU per pound with 20% moisture (air dry basis) to about 7,600 toabout 9,600 BTU per pound on a bone dry basis (or about 15 GJ/t with 20%moisture to about 18-22 GJ/t on a bone dry basis), and that agriculturalresidues, such as switchgrass, have an energy content of about 4,300 BTUper pound to about 7,300 BTU per pound (or about 10-17 GJ/t), dependingon the moisture content of the agricultural residue. In addition, thoseskilled in the art would known that charcoal has an energy content ofabout 12,800 BTU per pound. Accordingly, a skilled person wouldappreciate that the range of heat energy values following torrefactioncan also vary, with those biomass and/or biosolid material having alower initial heat energy value producing an end product having a lowerheat energy value compared to a biomass and/or biosolid material havinga higher initial heat energy value. In addition, as described herein,different factors can be varied, such as, without limitation, thedensity of the densified biomass, the temperature of the combustibleliquid, the submersion time of the densified biomass in the combustibleliquid, and the type of combustible liquid used, to obtain a particularheat energy value for a torrefied densified biomass and/or biosolidmaterial of the present disclosure.

The torrefied densified biomass and/or biosolid of the presentdisclosure may accordingly have a heat energy value of about 6,000 BTUper pound on a bone dry basis to about 13,000 BTU per pound on a bonedry basis, or any heat energy value therebetween, for example, fromabout 6,000 BTU per pound on a bone dry basis to about 12,000 BTU perpound on a bone dry basis, or any heat energy value therebetween; fromabout 6,000 BTU per pound on a bone dry basis to about 11,000 BTU perpound on a bone dry basis, or any heat energy value therebetween; fromabout 6,000 BTU per pound on a bone dry basis to about 10,000 BTU perpound on a bone dry basis, or any heat energy value therebetween; fromabout 6,000 BTU per pound on a bone dry basis to about 9,000 BTU perpound on a bone dry basis, or any heat energy value therebetween; fromabout 9,000 BTU per pound on a bone dry basis to about 13,000 BTU perpound on a bone dry basis, or any heat energy value therebetween, suchas, for example, about 9,500 BTU per pound on a bone dry basis; about10,000 BTU per pound on a bone dry basis; about 10,500 BTU per pound ona bone dry basis; about 11,000 BTU per pound on a bone dry basis; about11,500 BTU per pound on a bone dry basis; about 12,000 BTU per pound ona bone dry basis; about 12,500 BTU per pound on a bone dry basis on abone dry basis; about 13,000 BTU per pound, or any heat energy valuetherebetween. The heat energy value may also be expressed in terms ofgigajoules per metric tonne (GJ/t). The torrefied densified biomassand/or biosolid may therefore comprise a heat energy value of about 22GJ/t on a bone dry basis to about 27 GJ/t on a bone dry basis, or anyheat energy value therebetween, for example, from about 22 GJ/t on abone dry basis to about 26.5 GJ/t on a bone dry basis or any heat energyvalue therebetween; from about 22 GJ/tt on a bone dry basis to about 26GJ/t on a bone dry basis or any heat energy value therebetween; fromabout 22 GJ/t on a bone dry basis to about 26 GJ/t on a bone dry basisor any heat energy value therebetween; from about 22 GJ/t on a bone drybasis to about 25 GJ/t on a bone dry basis or any heat energy valuetherebetween; from about 22 GJ/t on a bone dry basis to about 24 GJ/t ona bone dry basis or any heat energy value therebetween; or from about 22GJ/t on a bone dry basis to about 23 GJ/t on a bone dry basis or anyheat energy value therebetween.

Furthermore, the torrefied densified biomass disclosed herein may have acarbon content of about 50 carbon % on a bone dry basis to about 65carbon % on a bone dry basis, or any amount therebetween. For example,without limitation, the carbon content of the torrefied densifiedbiomass may be about 51 carbon % on a bone dry basis, 52 carbon % on abone dry basis, 53 carbon % on a bone dry basis, 54 carbon % on a bonedry basis, 55 carbon % on a bone dry basis, 56 carbon % on a bone drybasis, 57 carbon % on a bone dry basis, 58 carbon % on a bone dry basis,59 carbon % on a bone dry basis, 60 carbon % on a bone dry basis, 61carbon % on a bone dry basis, 62 carbon % on a bone dry basis, 63 carbon% on a bone dry basis, 64 carbon % on a bone dry basis, 65 carbon % on abone dry basis, or any amount therebetween.

The torrefied end products are easily grindable into particulate and/orpowdered forms that are particularly suitable for use as fuels forgeneration of power and/or heat. Furthermore, the torrefied material iseasily transported and stored and are hydrophobic in nature.

A schematic flowchart is shown in FIG. 1 that illustrates an exemplaryprocess of the present disclosure for preparing a torrefied densifiedbiomass and/or biosolid material having a higher energy density value ascompared to a non-torrefied biomass material. In this embodiment, thestarting raw biomass material 2 is not densified and the process forpreparing the torrefied densified biomass material includes initialsteps of drying and densifying raw biomass material 2 into densifiedbiomass material 20. For the torrefaction process, a receiving container10 is filled with a combustible liquid 12, as described above.Combustible liquid 12 is heated up to a temperature in a range of about160° C. to about 320° C., and densified biomass material 20 is immersedin the hot combustible liquid 12 in receiving container 10. Densifiedbiomass material 20 is completely submerged in the hot combustibleliquid 12 to create an “oxygen-free” environment. The hot combustibleliquid 12 may be maintained at a temperature in a range of about 160° C.to about 320° C., or any temperature therebetween. Alternatively, thetemperature of the hot combustible liquid 12 may be varied during theprocess between about 160° C. and about 320° C. Whether combustibleliquid 12 is maintained at a certain temperature or varied during theprocess, the temperature of densified biomass 20 is increased from itsinitial temperature to a temperature in a range of about 160° C. toabout 320° C., or any temperature therebetween. During this heatingprocess, most of the moisture is driven out of densified biomass 20 anddensified biomass 20 takes in heat energy in an endothermic reaction.Densified biomass 20 also undergoes chemical and structural changes andexpels some VOCs contained within densified biomass 20. The resultingtorrefied densified biomass 30 is removed from receiving container 10and cooled in a cooling system 32.

Any type of densification process described in the art may be used inthe present process to produce a densified biomass material 20 fortorrefaction. For example, densifier 5 may be a pelletizer, as known inthe art, and may comprise an extrusion process for producing pellets(including, for example, a pellet mill extruder, a screw extruder), ahammer mill, a piston press, a wheel press or a briquetter for pressingbiomass into a briquette, or may involve agglomeration. Densificationmay also include the addition of pellet binders during the densificationprocess to ensure that pellet quality is maintained. The densificationprocess may also involve pre-heating and melting of the raw biomassmaterial 2 through mechanical action and friction and heat, resulting ina significant reduction of volume, elimination of some moisture and air,and an increase in temperature of the biomass. After raw biomassmaterial 2 is densified, the resulting densified biomass 20 proceedsthrough the torrefaction process.

The present disclosure also provides that a dryer 7 may be used toreduce the moisture content in raw biomass material 2 before and/orafter densification and before torrefaction. Those skilled in the artwill appreciate that any dryer known in the art may be used, such as,for example, the Altentech™ Biovertidryer™ (available from Altentech™Power Inc., Vancouver, BC, Canada), together with densifier 5. Thedrying process may be useful in further heating of the densified biomassmaterial 20 prior to torrefaction, thereby increasing the efficiency ofthe torrefaction process.

Dryer 7 and/or densifier 5 (or a combined dryer/densifier) may belocated near receiving container 10 containing combustible liquid 12.With such an arrangement, densified biomass 20 may be directlytransferred from densifier 5 and/or dryer 7 (or a combineddryer/densifier) to receiving container 10 without cooling the densifiedbiomass 20 in-between. Those skilled in the art will appreciate thatthrough the action of densifiers and melding raw material into a compactproduct, densifiers produce significant heat, thus resulting in a heateddensified product. Dryers known in the art also use significant heat toextract moisture from raw biomass, thus further increasing the heat of adensified product. Accordingly, densified biomass 20 is at a temperaturegreater than ambient temperature immediately following densificationand/or drying. Transfer of densified biomass 20 directly from densifier5 and/or dryer 7 (or a combined dryer/densifier) to receiving container10 may assist in further reducing the costs of torrefying biomass andincrease the efficiency of the process as the initial temperature ofdensified biomass 20 entering combustible liquid 12 is higher thanambient temperature. Alternatively, the densified biomass 20 may becooled before transferring from densifier 5 and/or dryer 7 (or acombined dryer/densifier) to receiving container 10.

Importantly, the present disclosure provides for densification prior tocontact with any type of oil; that is, raw biomass material 2 isdensified prior to contacting any oil of the combustible liquid (ordensified biomass 20 is used as the starting material). Those skilled inthe art will appreciate that fat and oil may interfere with steamabsorption and reduce pelletability. Fats and oils may be used duringpelleting, but generally to lubricate the die and ensure a smoothstart-up after the die cools off. Oil is mixed with raw biomaterialfollowing densification to purge the die prior to shutdown and is notfor actual pelletization of the biomass. In fact, oil-saturated biomassfrom a pellet press may be saved following pelletization for reuse in asubsequent shutdown sequence (see, for example, Kofman, P D. “Theproduction of wood pellets.” Coford Connects, Processing/Products No.10, pages 1-6, 2012). Accordingly, the present disclosure provides animproved torrefied densified biomass as compared to prior art processeswhich coat biomass with oil prior to densification.

Receiving container 10 may be any type of container that can be heatedto a temperature of up to about 320° C. and can hold hot combustibleliquid at a temperature of up to about 320° C. for extended periods oftime. It is, therefore, understood that receiving container 10 be of asimple design. For example, receiving container 10 may be a commerciallyavailable deep fryer exemplified by a PITCO® fryer (PITCO is aregistered trademark of Pitco Frialator, Inc., Burlington, Vt., U.S.A.),a VULCAN® fryer (VULCAN is a registered trademark of Vulcan-HartCorporation, Chicago, Ill., U.S.A.), a FRYMASTER® (FRYMASTER is aregistered trademark of Frymaster LLC, Shreveport, La., U.S.A.), aSouthbend fryer, or a DEAN® fryer (DEAN is a registered trademark ofFrymaster LLC, Shreveport, La., U.S.A.); or, receiving container 10 maybe any sized drum, tank, pot or other container that can be heateddirectly from below to a temperature of about 320° C., and that can holda combustible liquid at a temperature of about 320° C. for extendedperiods of time. Receiving container 10 is also sufficiently sized toreceive the desired amount of densified biomass 20 together with thecombustible liquid 12.

Combustible liquid 12 may be heated using a heat source directly belowreceiving container 10 or using an external heat source to heat thecombustible liquid 12, which can be transferred into receiving container10 once it reaches its operating temperature. The external heat sourcemay be, for example, a nuclear reactor with modest thermal output, afurnace that burns coal or natural gas, or a portion of the producedbiocoal, with or without additional heat exchangers.

It is understood that, to minimize costs of the exemplary processesdescribed herein, the size of receiving container 10 and the amount ofcombustible liquid 12 used may be limited to a size and amount that issufficient to completely submerge the particular quantity of densifiedbiomass 20 to be torrefied. Moreover, smaller amounts of combustibleliquid may also be used if densified biomass 20 comprises smaller-sizedpellets or briquettes. Accordingly, the exemplary processes describedherein may be varied in order to make the process more efficient andless costly, and can be adjusted according to a user's needs.

As described above, combustible liquid 12 may be heated to a temperaturein a range of about 160° C. to about 320° C., or any temperaturetherebetween, and the combustible liquid 12 may be maintained at thistemperature during the torrefaction process. By way of further example,the temperature that combustible liquid 12 may be heated to andmaintained at can vary in a range of between about 180° C. to about 320°C., or any temperature therebetween; between about 180° C. to about 300°C., or any temperature therebetween; between about 200° C. to about 320°C., or any temperature therebetween; between about 200° C. and about310° C., or any temperature therebetween; between about 200° C. andabout 300° C., or any temperature therebetween; between about 200° C.and about 290° C., or any temperature therebetween; between about 200°C. and about 280° C., or any temperature therebetween; between about200° C. and about 270° C., or any temperature therebetween; betweenabout 200° C. and about 260° C., or any temperature therebetween;between about 200° C. and about 250° C., or any temperaturetherebetween; between about 200° C. and about 240° C., or anytemperature therebetween; between about 220° C. and about 300° C., orany temperature therebetween; between about 220° C. and about 290° C.,or any temperature therebetween; between about 220° C. and about 280°C., or any temperature therebetween; between about 220° C. and about270° C., or any temperature therebetween; between about 220° C. andabout 260° C., or any temperature therebetween; between about 220° C.and about 250° C., or any temperature therebetween; between about 220°C. and about 240° C., or any temperature therebetween; or can be about162° C., 165° C., 168° C., 170° C., 172° C., 175° C., 178° C., 180° C.,181° C., 182° C., 183° C., 184° C., 185° C., 186° C., 187° C., 188° C.,189° C., 190° C., 191° C., 192° C., 193° C., 194° C., 195° C., 196° C.,197° C., 198° C., 199° C., 200° C., 201° C., 202° C., 203° C., 204° C.,205° C., 206° C., 207° C., 208° C., 209° C., 210° C., 211° C., 212° C.,213° C., 214° C., 215° C., 216° C., 217° C., 218° C., 219° C., 220° C.,221° C., 222° C., 223° C., 224° C., 225° C., 226° C., 227° C., 228° C.,229° C., 230° C., 231° C., 232° C., 233° C., 234° C., 235° C., 236° C.,237° C., 238° C., 239° C., 240° C., 241° C., 242° C., 243° C., 244° C.,245° C., 248° C., 250° C., 252° C., 255° C., 258° C., 260° C., 262° C.,264° C., 266° C., 268° C., 270° C., 272° C., 274° C., 276° C., 278° C.,280° C., 282° C., 284° C., 286° C., 288° C., 290° C., 292° C., 294° C.,296° C., 298° C., 300° C., 302° C., 304° C., 306° C., 308° C., 310° C.,312° C., 314° C., 316° C., 318° C., 320° C., or any temperaturetherebetween.

It is further contemplated that the temperature of combustible liquid 12may be heated in a step-wise fashion. This step-wise heating may be donein a single receiving container 10 such that the same combustible liquidis heated to an initial temperature and then heated to an increasedtemperature for torrefying densified biomass 20. Using a singlereceiving container reduces any costs that would be associated withtransferring densified biomass 20 between multiple receiving containers10, using multiple volumes of combustible liquid 12, and heatingmultiple volumes of combustible liquid 12.

Combustible liquid 12 may be heated to an initial lower temperatureprior to loading with densified biomass 20. Once densified biomass 20 issubmerged within combustible liquid 12 at the lower initial temperaturefor a certain period of time, combustible liquid 12 may be heated to ahigher temperature for torrefaction. Such a step-wise heating ofcombustible liquid 12 and densified biomass 20 may result in a moreefficient and less costly process, as the initial lower temperature maybe used for heating densified biomass 20 from its starting temperatureto a higher temperature and for releasing the majority of the moisturefrom densified biomass 20; the higher temperature, on the other hand,may be used for a shorter period of time for torrefying densifiedbiomass 20. Accordingly, less energy may be required as a highertemperature would be required for a shorter period of time. By way ofexample, combustible liquid 12 may be initially heated to a temperaturein a range of about 110° C. to about 200° C., or any temperaturetherebetween, such as, but not limited to, about 110° C., 112° C., 114°C., 116° C., 118° C., 120° C., 122° C., 124° C., 126° C., 128° C., 130°C., 132° C., 134° C., 136° C., 138° C., 140° C., 142° C., 144° C., 148°C., 150° C., 151° C., 152° C., 153° C., 154° C., 155° C., 156° C., 157°C., 158° C., 159° C., 160° C., 161° C., 162° C., 163° C., 164° C., 165°C., 166° C., 167° C., 168° C., 169° C., 170° C., 171° C., 172° C., 173°C., 174° C., 175° C., 176° C., 177° C., 178° C., 179° C., 180° C., 182°C., 185° C., 188° C., 190° C., 192° C., 195° C., 198° C., 200° C., orany temperature therebetween. Densified biomass 20 may be submergedwithin the lower temperature for about 2 minutes to about 30 minutes, orany amount of time therebetween, such as 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6,6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14,14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21,21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28,28.5, 29, 29.5, 30 minutes, or any amount of time therebetween.Following the initial period of the heat treatment, combustible liquid12, containing densified biomass 20 submerged therein, may be furtherheated to a temperature of about 180° C. to about 320° C., or anytemperature therebetween, such as, but not limited to, about 181° C.,182° C., 183° C., 184° C., 185° C., 186° C., 187° C., 188° C., 189° C.,190° C., 191° C., 192° C., 193° C., 194° C., 195° C., 196° C., 197° C.,198° C., 199° C., 200° C., 201° C., 202° C., 203° C., 204° C., 205° C.,206° C., 207° C., 208° C., 209° C., 210° C., 211° C., 212° C., 213° C.,214° C., 215° C., 216° C., 217° C., 218° C., 219° C., 220° C., 221° C.,222° C., 223° C., 224° C., 225° C., 226° C., 227° C., 228° C., 229° C.,230° C., 231° C., 232° C., 233° C., 234° C., 235° C., 236° C., 237° C.,238° C., 239° C., 240° C., 241° C., 242° C., 243° C., 244° C., 245° C.,248° C., 250° C., 252° C., 255° C., 258° C., 260° C., 262° C., 264° C.,266° C., 268° C., 270° C., 272° C., 274° C., 276° C., 278° C., 280° C.,282° C., 284° C., 286° C., 288° C., 290° C., 292° C., 294° C., 296° C.,298° C., 300° C., 302° C., 304° C., 306° C., 308° C., 310° C., 312° C.,314° C., 316° C., 318° C., 320° C., or any temperature therebetween.Densified biomass 20 may be torrefied in the higher temperature forabout 2 minutes to about 60 minutes, or any amount of time therebetween,such as 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, 5minutes, 5.5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes, 8minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 10.5 minutes,11 minutes, 11.5 minutes, 12 minutes, 12.5 minutes, 13 minutes, 13.5minutes, 14 minutes, 14.5 minutes, 15 minutes, 15.5 minutes, 16 minutes,16.5 minutes, 17 minutes, 17.5 minutes, 18 minutes, 18.5 minutes, 19minutes, 19.5 minutes, 20 minutes, 20.5 minutes, 21 minutes, 21.5minutes, 22 minutes, 22.5 minutes, 23 minutes, 23.5 minutes, 24 minutes,24.5 minutes, 25 minutes, 25.5 minutes, 26 minutes, 26.5 minutes, 27minutes, 27.5 minutes, 28 minutes, 28.5 minutes, 29 minutes, 29.5minutes, 30 minutes, 32 minutes, 34 minutes, 36 minutes, 38 minutes, 40minutes, 42 minutes, 44 minutes, 46 minutes, 48 minutes, 50 minutes, 52minutes, 54 minutes, 56 minutes, 58 minutes, 60 minutes, or any amountof time therebetween.

The present disclosure contemplates densified biomass material 20 beingloaded directly into receiving container 10. Alternatively, densifiedbiomass material 20 may be loaded into a holder 22, which is thenimmersed within receiving container 10.

To allow direct contact of densified biomass material 20 withcombustible liquid 12 when holder 22 is used in the exemplary process,holder 22 may be any type of holder that can fit the densified feedstockto be torrefied and fit within receiving container 10 and that is porousto combustible liquid 12 in receiving container 10, but not to thedensified feedstock. As such, holder 22 prevents densified biomass 20 ortorrefied densified biomass 30 contained in holder 22 from fallingoutside holder 22, while allowing combustible liquid 12 to flow throughholder 22 to heat and torrefy densified biomass 20. For example, withoutlimitation, holder 22 may be a wire-strainer type basket or wire meshbasket or other type of basket with perforations within its outer walls.It is understood that holder 22 can withstand the heat of combustibleliquid 12 and can be heated to a temperature of up to about 320° C. forextended periods of time.

Given that densified biomass 20 is completely submerged withincombustible liquid 12, which is heated to a temperature in a range ofabout 160° C. to about 280° C., or any temperature therebetween,densified biomass 20 is heated up to a temperature in a range of about160° C. to about 320° C., or any temperature therebetween, by completionof the torrefaction process. By way of further example, the temperatureof torrefied densified biomass 30 at the end of the exemplary processcan vary in a range of between about 180° C. to about 320° C., or anytemperature therebetween; between about 180° C. to about 300° C., or anytemperature therebetween; between about 200° C. and about 320° C., orany temperature therebetween; between about 200° C. and about 310° C.,or any temperature therebetween; between about 200° C. and about 300°C., or any temperature therebetween; between about 200° C. and about290° C., or any temperature therebetween; between about 200° C. andabout 280° C., or any temperature therebetween; between about 200° C.and about 270° C., or any temperature therebetween; between about 200°C. and about 260° C., or any temperature therebetween; between about200° C. and about 250° C., or any temperature therebetween; betweenabout 200° C. and about 240° C., or any temperature therebetween;between about 220° C. and about 300° C., or any temperaturetherebetween; between about 220° C. and about 290° C., or anytemperature therebetween; between about 220° C. and about 280° C., orany temperature therebetween; between about 220° C. and about 270° C.,or any temperature therebetween; between about 220° C. and about 260°C., or any temperature therebetween; between about 220° C. and about250° C., or any temperature therebetween; between about 220° C. andabout 240° C., or any temperature therebetween; or can be about 162° C.,165° C., 168° C., 170° C., 172° C., 175° C., 178° C., 180° C., 181° C.,182° C., 183° C., 184° C., 185° C., 186° C., 187° C., 188° C., 189° C.,190° C., 191° C., 192° C., 193° C., 194° C., 195° C., 196° C., 197° C.,198° C., 199° C., 200° C., 201° C., 202° C., 203° C., 204° C., 205° C.,206° C., 207° C., 208° C., 209° C., 210° C., 211° C., 212° C., 213° C.,214° C., 215° C., 216° C., 217° C., 218° C., 219° C., 220° C., 221° C.,222° C., 223° C., 224° C., 225° C., 226° C., 227° C., 228° C., 229° C.,230° C., 231° C., 232° C., 233° C., 234° C., 235° C., 236° C., 237° C.,238° C., 239° C., 240° C., 241° C., 242° C., 243° C., 244° C., 245° C.,248° C., 250° C., 252° C., 255° C., 258° C., 260° C., 262° C., 264° C.,266° C., 268° C., 270° C., 272° C., 274° C., 276° C., 278° C., 280° C.,282° C., 284° C., 286° C., 288° C., 290° C., 292° C., 294° C., 296° C.,298° C., 300° C., 302° C., 304° C., 306° C., 308° C., 310° C., 312° C.,314° C., 316° C., 318° C., 320° C., or any temperature therebetween. Oneof skill in the art will appreciate that the temperature of torrefieddensified biomass 30 at the end of the torrefaction process, prior toremoval from receiving container 10, will depend on the starting rawmaterial, the time that densified biomass 20 is submerged within heatedcombustible liquid 12, the type of combustible liquid 12 used, and thetemperature of combustible liquid 12.

During submersion of the densified biomass 20 within combustible liquid12 and during the torrefaction process, densified biomass 20 absorbscombustible liquid 12 such that the resulting torrefied densifiedbiomass 30 retains some absorbed combustible liquid 12. The amount ofcombustible liquid 12 absorbed by the densified biomass 20 and retainedin the post-torrefaction densified biomass 30 depends upon severaldifferent factors including, for example, the physico-chemicalproperties of the starting feedstock, the density of the densifiedbiomass 20, the amount of starting feedstock, the submersion time of thedensified biomass 20 in the combustible liquid 12, the combustibleliquid 12 used, and the temperature of the combustible liquid 12. Aswill be illustrated and described further in Examples 4 and 5, theabsorption of combustible liquid 12 by densified biomass 20 does notoccur at a constant rate. Combustible liquid 12 is initially absorbed ata higher rate compared to absorption rates occurring later in thetorrefaction process. For example, the rate of absorption at thebeginning of the torrefaction process may be between about 9% to about18% w/w combustible liquid per mass of the input bone dry densifiedbiomass, or any rate therebetween such as, without limitation, about10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, or any rate therebetween.Following the initial higher rate of absorption of the combustibleliquid 12, the absorption rate decreases and remains at a fairlyconstant rate for a period of time during the torrefaction process. Thislower rate occurring during the mid-portion of the torrefaction processmay be between about 6% to about 14% w/w combustible liquid per mass ofthe input bone dry densified biomass, or any rate therebetween such as,without limitation, about 7%, 8%, 9%, 10%, 11%, 12%, 13%, or any ratetherebetween. It was discovered that if densified biomass 20 issubmersed in combustible liquid 12 for longer periods of time, rate ofabsorption of the combustible liquid 12 by the densified biomass 20decreases substantially. For example, the rate of absorption duringlater periods of the torrefaction process may be between about 2% toabout 10% w/w combustible liquid per mass of the densified biomass ofthe initial rate of absorption, or any rate therebetween such as,without limitation, about 3%, 4%, 5%, 6%, 7%, 8%, 9%, or any ratetherebetween. The rate of absorption of combustible liquid 12 bydensified biomass 20 may also fall to a negative rate if the densifiedbiomass 20 is submersed within combustible liquid 12 for an extensiveperiod of time. It appears that some of the combustible liquid 12absorbed by the densified biomass 20 during the earlier stages of thetorrefaction process may be released from torrefied densified biomass 30as the torrefaction process is maintained for increasingly extendedperiods of time. As disclosed above, the time ranges during which therate of absorption occurs at higher rates, constant rates, lower ratesof absorption, or negative rates; i.e., loss of the combustible liquidby torrefied densified biomass 20 will depend on one or more of thetemperature of the combustible liquid 12, the physico-chemicalproperties of the starting feedstock, the amount of starting feedstock,the combustible liquid 12, the type of combustible liquid 12 used, andother factors. However, it is apparent that the rate of absorption ofcombustible liquid 12 by densified biomass 20 varies during thetorrefaction process, such that, the rate of absorption is initiallyhigher, subsequently diminishing over time and, eventually, potentiallyresulting in loss of some combustible liquid 12 absorbed earlier in theprocess. Based on these findings, the duration of the torrefactionprocess may be varied to obtain torrefied densified biomass 30 withdifferent amounts of combustible liquid 12 absorbed therein.

The amount of time that densified biomass 20 is submerged withincombustible liquid 12 may vary depending on different variables, such asfor example, the properties of the starting feedstock, including itssize and initial temperature, the size of receiving container 10, theamount of the starting feedstock for torrefaction, the amount ofcombustible liquid 12, the type of combustible liquid 12, and thephysico-chemical properties of torrefied densified biomass 30 that isdesired, such as the mass, amount of oil contained therein, carboncontent, hydrophobic nature and the heat energy value (BTU per pound orGJ/t). By way of example, the submersion time of densified biomass 20 incombustible liquid 12 may vary from about 2 minutes to about 120minutes, or any amount of time therebetween; such as for example, fromabout 2 minutes to about 110 minutes, or any amount of timetherebetween; from about 2 minutes to about 100 minutes, or any amountof time therebetween; from about 2 minutes to about 90 minutes, or anyamount of time therebetween; from about 2 minutes to about 80 minutes,or any amount of time therebetween; from about 2 minutes to about 75minutes, or any amount of time therebetween; from about 2 minutes toabout 70 minutes, or any amount of time therebetween; from about 2minutes to about 65 minutes, or any amount of time therebetween; fromabout 2 minutes to about 60 minutes, or any amount of time therebetween;from about 2 minutes to about 55 minutes, or any amount of timetherebetween; from about 2 minutes to about 50 minutes, or any amount oftime therebetween; from about 2 minutes to about 45 minutes, or anyamount of time therebetween; from about 2 minutes to about 40 minutes,or any amount of time therebetween; from about 2 minutes to about 35minutes, or any amount of time therebetween; from about 2 minutes toabout 30 minutes, or any amount of time therebetween; from about 2minutes to about 25 minutes, or any amount of time therebetween; fromabout 2 minutes to about 20 minutes, or any amount of time therebetween;from about 5 minutes to about 60 minutes, or any amount of timetherebetween; from about 5 minutes to about 55 minutes, or any amount oftime therebetween; from about 5 minutes to about 50 minutes, or anyamount of time therebetween; from about 5 minutes to about 45 minutes,or any amount of time therebetween; from about 5 minutes to about 40minutes, or any amount of time therebetween; from about 5 minutes toabout 35 minutes, or any amount of time therebetween; from about 5minutes to about 30 minutes, or any amount of time therebetween; fromabout 5 minutes to about 25 minutes, or any amount of time therebetween;from about 5 minutes to about 20 minutes, or any amount of timetherebetween; from about 5 minutes to about 15 minutes, or any amount oftime therebetween; or about 2 minutes, 2.5 minutes, 3 minutes, 3.5minutes, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes, 6 minutes, 6.5minutes, 7 minutes, 7.5 minutes, 8 minutes, 8.5 minutes, 9 minutes, 9.5minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, 21minutes, 22 minutes, 23 minutes, 24 minutes, 25 minutes, 26 minutes, 27minutes, 28 minutes, 29 minutes, 30 minutes, 32 minutes, 34 minutes, 36minutes, 38 minutes, 40 minutes, 42 minutes, 44 minutes, 46 minutes, 48minutes, 50 minutes, 52 minutes, 54 minutes, 56 minutes, 58 minutes, 60minutes, or any amount of time therebetween.

Following submersion of densified biomass 20 in combustible liquid 12for the time desired, torrefied densified biomass 30 is retrieved fromreceiving container 10. If densified biomass 20 is directly loaded intoreceiving container 10, any type of utensil may be used to retrievetorrefied densified biomass 30 from receiving container 10. Preferably,the utensil used will limit the amount of combustible liquid 12 that isremoved with torrefied densified biomass 30, as the present processcontemplates reuse of the combustible liquid 12. By way of example, theutensil may be a perforated-type of utensil, such as, withoutlimitation, a slotted spoon, or may be a pair of forceps, tweezers,tongs, or the like. If holder 22 is used to load densified biomass 20into receiving container 10, then holder 22, along with torrefieddensified biomass 30 contained therein, is removed from receivingcontainer 10.

To minimize the amount of combustible liquid 12 that is removed alongwith torrefied densified biomass 30, and thereby, be able to reuse asmuch combustible liquid 12 as possible, torrefied densified biomass 30,or holder 22 containing torrefied densified biomass 30, may be heldabove receiving container 10 for about 15 seconds to about 150 seconds,or any time therebetween, to drain torrefied densified biomass 30 ofcombustible liquid 12 and drip combustible liquid 12 into receivingcontainer 10 for reuse. For example, without limitation, torrefieddensified biomass 30, or holder 22, may be held above receivingcontainer 10 for about 15 seconds, 16 seconds, 17 seconds, 18 seconds,19 seconds, 20 seconds, 21 seconds, 22 seconds, 23 seconds, 24 seconds,25 seconds, 26 seconds, 27 seconds, 28 seconds, 29 seconds, 30 seconds,31 seconds, 32 seconds, 33 seconds, 34 seconds, 35 seconds, 36 seconds,37 seconds, 38 seconds, 39 seconds, 40 seconds, 41 seconds, 42 seconds,43 seconds, 44 seconds, 45 seconds, 48 seconds, 50 seconds, 52 seconds,55 seconds, 58 seconds, 60 seconds, 65 seconds, 70 seconds, 75 seconds,80 seconds, 85 seconds, 90 seconds, 95 seconds, 100 seconds, 105seconds, 110 seconds, 115 seconds, 120 seconds, 125 seconds, 130seconds, 135 seconds, 140 seconds, 145 seconds, 150 seconds, or anyamount of time therebetween. If time permits, a skilled person willappreciate that torrefied densified biomass 30, or holder 22, may beheld above receiving container 10 for longer periods of time to maximizethe amount combustible liquid 12 retained in receiving container 10.Accordingly, the exemplary process described herein maximizes retentionof oil or combustible liquid 12 in receiving container 10, rather thanabsorption into the torrefied densified biomass, to reduce costs ofreplenishing the oil for torrefaction with each cycle.

The exemplary process further provides a cooling step, wherein torrefieddensified biomass 30 is placed in a cooling system 32 to cool torrefieddensified biomass 30 to near-ambient temperatures until it can be safelyhandled for packaging, storing, use, or transportation. Cooling system32 may be, for example, a cold water bath with the water at asufficiently cold temperature to cool torrefied densified biomass 30 toa near-ambient temperature. For example, without limitation, the coldwater bath may have water at a temperature of about 0° C. to about 100°C., or any temperature therebetween, such as, without limitation, about0° C., 2° C., 4° C., 6° C., 8° C., 10° C., 12° C., 14° C., 16° C., 18°C., 20° C., 22° C., 24° C., 26° C., 28° C., 30° C., 32° C., 34° C., 36°C., 38° C., 40° C., 42° C., 44° C., 46° C., 48° C., 50° C., 52° C., 54°C., 56° C., 58° C., 60° C., 62° C., 64° C., 68° C., 70° C., 72° C., 74°C., 76° C., 78° C., 80° C., 82° C., 84° C., 86° C., 88° C., 90° C., 92°C., 94° C., 96° C., 98° C., 100° C., or any temperature therebetween.Torrefied densified biomass 30 may be immersed in the cold water bathfor about 0.5 to about 20 minutes, or any amount of time therebetween,such as, without limitation, 0.5 minutes, 1 minutes, 2 minutes, 3minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, orany amount of time therebetween. It is understood that torrefieddensified biomass 30 may be left in the cold water bath for longerperiods of time, and the amount of time will vary depending on a numberof factors, such as, the size of torrefied densified biomass 30, thesize and temperature of the cold water bath, the starting temperature oftorrefied densified biomass 30 (i.e., its temperature at the point it isretrieved from receiving container 10), and the desired temperature ofthe torrefied densified biomass 30 for handling. The torrefactionprocess produces a hydrophobic torrefied biomass. Accordingly, coolingtorrefied densified biomass 30 in water does not generally result insignificant absorption of water or an increase in weight of thetorrefied densified biomass 30. However, the amount of water absorbed bythe torrefied densified biomass 30 is relative to the amount of timethat densified biomass 20 is retained in hot combustible liquid 12 andthe temperature of combustible liquid 12. It is further contemplatedthat torrefied densified biomass may also be cooled in a step-wisefashion, such that an initial cold water bath with water at atemperature between about 50° C. to about 100° C., or any temperaturetherebetween, is used, followed by a cold water bath at a temperaturebetween about 0° C. to about 50° C., or any temperature therebetween.This step-wise cooling may increase the efficiency of the cooling stepand thereby reduce costs and increase throughput.

Torrefied densified biomass 30 may be placed directly into coolingsystem 32 without holder 22, or holder 22 containing torrefied densifiedbiomass 30 therein may be placed into cooling system 32. Accordingly,torrefied densified biomass 30 may be extracted from the cold water bathin a manner similar to how it is retrieved from receiving container 10,as described above. The use of a cooling system 32, such as a cold waterbath, does not require significant energy or resources to operate, thusproviding a further cost-savings and efficiency. Furthermore, collectionof any steam expelled during the cooling process may also be used inother stages of the process, as described in more detail below.

Further, as mentioned above, the amount of combustible liquid 12absorbed and retained within torrefied densified biomass 30 may bevaried depending on various factors, including the duration of thetorrefaction process and submersion of densified biomass 20 withincombustible liquid 12, the temperature of the combustible liquid 12, theproperties of the starting feedstock, the amount of the startingfeedstock, and the type of combustible liquid 12 used, amongst otherfactors. Consequently, the heat energy value of torrefied densifiedbiomass 30 may also be tailored by adjusting the variables, such as theduration of the torrefaction process and submersion of densified biomass20 within combustible liquid 12, the temperature of the combustibleliquid 12, the properties of the starting feedstock, the amount of thestarting feedstock, and the combustible liquid 12 used, amongst otherfactors.

Another exemplary process of the present disclosure is shown in FIG. 2.In this embodiment, the starting raw biomass material is densified suchthat no densification step is required prior to immersion in combustibleliquid 12. Densified biomass 20 can be any biomass material that isreadily commercially available as a densified biomass product. Otherthan the initial starting material, the remaining steps of thisembodiment are the same as those described in relation to FIG. 1.

As shown in FIGS. 1 and 2, a gas collection and condenser system 40comprising a plurality of pipes may be used for connecting to receivingcontainer 10 and cooling system 32. System 40 may comprise a series ofinlets and outlets, with an inlet disposed in each of receivingcontainer 10 and cooling system 32 above the liquid level of combustibleliquid 12 and the cooling water in cooling system 32, respectively. Theinlet disposed in receiving container 10 is for collecting VOCs andsteam, and the inlet disposed in cooling system 32 is for collectingsteam upon cooling of the torrefied densified biomass. An inlet may alsobe disposed in densifier 5 or dryer 7 (or a combined dryer/densifier) tocapture any steam that is expelled during the densification and dryingprocesses. The mixture of VOCs and steam may be further processed andcondensed in system 40. The mixture may be separated into bio-liquidsand gases that contain CO, CO₂ and perhaps also H₂, CH₄ and other tracevolatiles. The gases may be burnt to help heat the combustible liquid 12in receiving container 10 or to provide energy for dryer 7 or densifier5 (or a combined dryer/densifier). If the gases are used in theexemplary processes, outlets of system 40 will be disposed within theheat sources for heating combustible liquid 12 and within the dryer 7and densifier 5 (or a combined dryer/densifier) to assist in operatingthese machines. Alternatively, the gases may be used or sold separatelyas feedstock for other chemical synthesis processes. The bio-liquidsobtained from the non-volatile vapors and steam may be reused in coolingsystem 32 or potentially in a steam generator or boiler for heatingcombustible liquid 12. The present disclosure, therefore, provides for aheat exchange system that results in a more energy-efficient process.

It is further contemplated that the exemplary processes described hereinmay be continuous, semi-continuous or batch processes. With acontinuous, semi-continuous or batch process, the various steps of theprocess may be connected by a conveyor-type system or other type ofsystem to allow continuous transporting of densified biomass 20 orholder 22 containing densified biomass 20 therein through the presentprocesses as described herein. The present disclosure thereforecontemplates a system for carrying out the exemplary torrefactionprocesses disclosed herein. In such a system, a conveyor or other typeof transport system may be used to carry the raw biomass material,whether densified to begin with or not, through the processes describedin FIGS. 1 and 2. Accordingly, the raw biomass material 2 is broughtfrom the densifier 5/dryer 7 or receiving container 10 through theprocess to the cooling system 32, where the torrefied densified biomass30 is retrieved and available for handling, transport, use, shipping,etc. Any type of continuous system, semi-continuous system or batchsystem contemplated herein is a straight-line, simple to design, easilyoperatable and efficient system, with limited complexity and engineeringrequired.

The exemplary processes described herein may further comprise a step ofcleaning the torrefied densified biomass 30. This step of cleaning maycomprise a screening process, wherein a screening device is used toseparate fines and any other waste particles from torrefied densifiedbiomass 30. Alternatively, this step of cleaning may comprise a washingstep, wherein torrefied densified biomass 30 is washed in a water bathto remove residual combustible oil adhering to the outer surface of thetorrefied densified biomass 30. The cleaning of the torrefied densifiedbiomass 30 may also comprise both a screening step and a washing step.

Another embodiment of the present disclosure relates to an exemplaryprocess 100 illustrated in FIG. 3 wherein a selected biomass orbiosolids feedstock is delivered to a pellet press or briquetter 105wherein the feedstock is densified and extruded as pellets or pressedinto briquettes (i.e., densified biomass 20) which are transferred by apellet feed conveyer 110 into a torrefusion reactor 115. The supply ofthe selected biomass or biosolids feedstock to pellet press orbriquetter 105 may be continuous, semi-continuous or in batches, therebyresulting in a continuous, semi-continuous or batch throughput process100. The torrefusion reactor 115 contains a volume of heated combustibleoil 12 wherein the pellets 20 are submerged and torrefied for a selectedperiod of time. The combustible oil 12 contained in the torrefusionreactor 115, is maintained at a temperature from the range of about 160°C. to about 320° C. The torrefusion reactor 115 has components thatcontrollably maintain the pellets 20 submerged in the heated combustibleoil 12 while controllably conveying the submerged pellets 20 from theinput end to the output end of the torrefusion reactor 115. Thesubmerged pellets 20 are torrefied during their transport from the inputend to the output end of the torrefusion reactor 115 via conveyor 110(or any other suitable conveyor belt that allows continuous orsemi-continuous transport of the pellets through the process 100). Theduration of time for transport of the submerged pellets 20 from theinput end to the output end of the torrefusion reactor 115 can becontrollably varied from about 2 minutes to about 120 minutes (or longerif so desired). After leaving the output end of the torrefusion reactor115, the torrefied pellets are conveyed on conveyor 110 (or any othersuitable conveyor belt that allows continuous or semi-continuoustransport of the pellets through the process 100) to a cooler 120 fromwhich they are conveyed into and through a screening device 125 whichseparates fines from the torrefied pellets. Finally, the screenedtorrefied pellets are conveyed into a finished product bin 130 viaconveyor 110 (or any other suitable conveyor belt that allows continuousor semi-continuous transport of the pellets through the process 100).

Heat and gases produced during torrefaction of the pellets in thetorrefusion reactor 115 are collected in a torgas collection hood 160under a vacuum force created by torgas fan 170 which conveys the heatand torrefaction gases to the torgas burner 145. The torgas burner 145combines and combusts the torrefaction gases to produce heated air whichis then conveyed to the hot side of an air-to-oil heat exchanger 150.The torgas burner 145 and thermal energy from the external burner iscombined prior to the heat exchanger 150. The combustible oil containedwithin the torrefusion reactor 115 is maintained at a selectedtemperature by constant circulation by an oil pump 152 through an oilfilter 154 and into the cool side of the air-to-oil heat exchanger 150wherein it is heated by the heated air incoming from the torgas burner145. The heated combustible oil is then conveyed back into thetorrefusion reactor 115. The air-to-oil heat exchanger 150 is vented 158to the atmosphere. Optionally, the screened fines 135 may also beconveyed to a burner 140 for production of thermal energy, and thethermal energy then routed to a torgas burner 145.

Another embodiment of the present disclosure relates to an exemplaryprocess 200 illustrated in FIG. 4 wherein a selected biomass orbiosolids feedstock is delivered to a pellet press or briquetter 202wherein the feedstock is densified and extruded as pellets or pressedinto briquettes which are transferred by a pellet feed conveyer 205 intoa torrefusion reactor 210. The supply of the selected biomass orbiosolids feedstock to pellet press or briquetter 202 may be continuous,semi-continuous or in batches, thereby resulting in a continuous,semi-continuous or batch throughput process 200. The torrefusion reactor210 contains a volume of heated combustible oil wherein the pellets aresubmerged and torrefied for a selected period of time. The combustibleoil contained in the torrefusion reactor 210, is maintained at atemperature from the range of about 160° C. to about 320° C. Thetorrefusion reactor 210 has components that controllably maintain thepellets submerged in the heated combustible oil while controllablyconveying the submerged pellets from the input end to the output end ofthe torrefusion reactor 210 via conveyer 205 or another conveyor beltthat allows continuous or semi-continuous transport of the pelletsthrough the process 200. The submerged pellets are torrefied duringtheir transport from the input end to the output end of the torrefusionreactor 210. The duration of time for transport of the submerged pelletsfrom the input end to the output end of the torrefusion reactor 210 canbe controllably varied from about 2 minutes to about 120 minutes (orlonger if so desired). After leaving the output end of the torrefusionreactor 210, the torrefied pellets are conveyed by conveyor 205 (or anyother suitable conveyor belt that allows continuous or semi-continuoustransport of the pellets through the process 200) into a water bathcooler 215 which receives a constant supply of fresh water 212. Residualcombustible oil adhering to the surface of the torrefied pelletsconveyed from the torrefusion reactor 210 is washed away from thetorrefied pellets into the wash water which is then separated from thewashed torrefied pellets. The washed torrefied pellets are conveyed intoa finished product bin 220 by conveyor 205 (or any other suitableconveyor belt that allows continuous or semi-continuous transport of thepellets through the process 200).

Heat and gases produced during torrefaction of the pellets in thetorrefusion reactor 210 are collected in a torgas collection hood 250under a vacuum force created by a torgas fan 255 which conveys the heatand torrefaction gases to a torgas burner 260. The torgas burner 260combines and combusts the torrefaction gases with a supply of thermalenergy from an external burner 262 to produce heated air which is thenconveyed to the hot side of an air-to-oil heat exchanger 235. Thecombustible oil contained within the torrefusion reactor 210 ismaintained at a selected temperature by constant circulation by an oilpump 225 through an oil filter 230 and into the cool side of theair-to-oil heat exchanger 235 wherein it is heated by the heated airincoming from the torgas burner 260. The heated combustible oil is thenconveyed back into the torrefusion reactor 210. The air-to-oil heatexchanger 235 is vented 237 to the atmosphere.

Either fresh water or the wash water from the water bath cooler 215 isoptionally routed to equipment 275 that can receive an incoming biomassfeedstock from a hopper referred to in FIG. 4 as a “raw salty hog” 270,that may need desalinization processing. Such biomass feedstocks areexemplified by hog fuel wastestreams produced from processing ofharvested logs that have been transported on and/or stored on saltwaterwaterways, which may require desalinization. The wash water is blendedwith the biomass feedstock in desalting and dewatering equipment 275.The salinized wash water recovered from the desalting and dewateringequipment may optionally be disposed of as an effluent 272, while thedesalted and dewatered biomass feedstock is conveyed to the pellet press202 for densification and extrusion as pellets.

Representative illustrations of a small scale torrefusion reactor foruse as torrefusion reactor 115, 210 are shown in FIGS. 5(A), 5(B), 6(A)and 6(B). Torrefusion reactor 115, 210 may comprise a mechanism forcontinuously or semi-continuously conveying densified biomass 20 throughthe reactor 115, 210, or for conveying densified biomass 20 in batchesthrough the reactor 115, 210, such as by way of conveyor 110, 205 (orany other suitable conveyor belt that allows continuous orsemi-continuous transport of the densified biomass 20 through process100, 200). Conveyor 110, 205 may be hand-operated,electronically-operated, battery-operated, solar-operated, or otherwisepowered to convey densified biomass 20 into and through the torrefusionreactor 115, 210 and torrefied densified biomass 30 out of thetorrefusion reaction 115, 210. As shown in FIGS. 5(B), 6(A) and 6(B),the torrefusion reaction may comprise holder 22 or other type of intakehopper/feeder that operates as a densified biomass/biosolids meteringbin and comprises a notch, slit, hole, space or any other type ofopening 280 at the point of contact with conveyor 110, 205 between thebottom of holder 22 and conveyor 110, 205, such that the densifiedbiomass 20 may be gravity fed from the holder 22 onto the movingconveyor 110, 205 as the conveyor moves. The throughput of the densifiedbiomass 20 onto conveyer 110, 205 and through process 100, 200 may becontrolled by adjusting the size of the notch, slit, hole, space orother type of opening 280 in or at the bottom of holder 22 and/or byadjusting the amount, size, weight and thickness of the bed of densifiedbiomass 20 placed in holder 22. The direction of rotation of conveyor110, 205 is shown in FIG. 6(B). Arrow (A) represents the direction ofrotation of conveyor 110, 205 to carry the densified biomass 20 into thecombustible liquid for a certain period of time and then conveying thetorrefied densified biomass 30 out of the combustible liquid. Arrow (B),shown in shadow, indicates that conveyor 110, 205 may be an endlessconveyor belt that can continuously or semi-continuously move densifiedbiomass 20 through the torrefaction processes disclosed herein. It willbe understand that in a full-scale, operational throughput process, thisconveyor 110, 205 may continue to convey the torrefied densified biomass30 into water bath cooler 215. An exemplary size for a small scaletorrefusion reactor 115, 210 is shown in Table A below.

TABLE A Torrefusion Reactor Size Reactor Length (feet) 36 Reactor Width(feet) 5 Conveyor Thickness (inches) 4 Retention/Submersion time(minutes) 15 Bulk Density (lbs/ft³) 40 Fill Factor (%) 100% Mass ofConveyor Mat (lbs/ft³) 2,400 Mass of Conveyor Mat (MT) 1.09 ConveyorCycles per Hour 4 Input per Hour (MT) 4.355 Output per Hour @ 80% (MT)3.484 Operating Hours per Day 24.00 Operating Hours per Week 7.00Operating Weeks per Year 50.00 Uptime (%) 80 Total Capacity (input)(MT/annum) 29,262 Total Capacity (output) (MT/annum) 23,410

Torrefied densified biomass 30 produced by the processes describedherein comprises about 2% to about 25% w/w combustible liquid followingtorrefaction (i.e., torrefied densified biomass 30 absorbs about 2% toabout 25% w/w combustible liquid during the process), or any amounttherebetween. For example, without limitation, the amount of combustibleliquid 12 absorbed and retained within torrefied densified biomass 30may be about 2% to about 25% w/w combustible liquid, or any amounttherebetween; about 2% to about 24% w/w combustible liquid, or anyamount therebetween; about 2% to about 23% w/w combustible liquid, orany amount therebetween; about 2% to about 22% w/w combustible liquid,or any amount therebetween; about 2% to about 21% w/w combustibleliquid, or any amount therebetween; about 2% to about 20% w/wcombustible liquid, or any amount therebetween; about 2% to about 19%w/w combustible liquid, or any amount therebetween; about 2% to about18% w/w combustible liquid, or any amount therebetween; about 2% toabout 17% w/w combustible liquid, or any amount therebetween; such as,for example, 3% w/w combustible liquid, 4% w/w combustible liquid, 5%w/w combustible liquid, 6% w/w combustible liquid, 7% w/w combustibleliquid, 8% w/w combustible liquid, 9% w/w combustible liquid, 10% w/wcombustible liquid, 11% w/w combustible liquid, 12% w/w combustibleliquid, 13% w/w combustible liquid, 14% w/w combustible liquid, 15% w/wcombustible liquid, 16% w/w combustible liquid, or any amounttherebetween.

Torrefied densified biomass 30 produced by the processes of the presentdisclosure may further have a heat energy value of about 6,000 BTU perpound on a bone dry basis to about 13,000 BTU per pound on a bone drybasis, or any heat energy value therebetween, for example, from about6,000 BTU per pound on a bone dry basis to about 12,000 BTU per pound ona bone dry basis, or any heat energy value therebetween; from about6,000 BTU per pound on a bone dry basis to about 11,000 BTU per pound ona bone dry basis, or any heat energy value therebetween; from about6,000 BTU per pound on a bone dry basis to about 10,000 BTU per pound ona bone dry basis, or any heat energy value therebetween; from about6,000 BTU per pound on a bone dry basis to about 9,000 BTU per pound ona bone dry basis, or any heat energy value therebetween; or from about9,000 BTU per pound on a bone dry basis to about 13,000 BTU per pound ona bone dry basis, or any heat energy value therebetween; such as, forexample, about 9,500 BTU per pound on a bone dry basis; about 10,000 BTUper pound on a bone dry basis; about 10,500 BTU per pound on a bone drybasis; about 11,000 BTU per pound on a bone dry basis; about 11,500 BTUper pound on a bone dry basis; about 12,000 BTU per pound on a bone drybasis; about 12,500 BTU per pound on a bone dry basis; about 13,000 BTUper pound on a bone dry basis, or any heat energy value therebetween.Alternatively, torrefied densified biomass 30 may comprise a heat energyvalue of about 22 GJ/t on a bone dry basis to about 27 GJ/t on a bonedry basis, or any heat energy value therebetween, for example, fromabout 22 GJ/t on a bone dry basis to about 26.5 GJ/t on a bone dry basisor any heat energy value therebetween; from about 22 GJ/t on a bone drybasis to about 26 GJ/t on a bone dry basis or any heat energy valuetherebetween; from about 22 GJ/t on a bone dry basis to about 26 GJ/t ona bone dry basis or any heat energy value therebetween; from about 22GJ/t on a bone dry basis to about 25 GJ/t on a bone dry basis or anyheat energy value therebetween; from about 22 GJ/t on a bone dry basisto about 24 GJ/t on a bone dry basis or any heat energy valuetherebetween; or from about 22 GJ/t on a bone dry basis to about 23 GJ/ton a bone dry basis, or any heat energy value therebetween.

The torrefied densified biomass 30 produced by the processes disclosedherein may also have a carbon content of about 50 carbon % on a bone drybasis to about 65 carbon % on a bone dry basis, or any amounttherebetween. For example, without limitation, the carbon content of thetorrefied densified biomass 30 may be about 51 carbon % on a bone drybasis, 52 carbon % on a bone dry basis, 53 carbon % on a bone dry basis,54 carbon % on a bone dry basis, 55 carbon % on a bone dry basis, 56carbon % on a bone dry basis, 57 carbon % on a bone dry basis, 58 carbon% on a bone dry basis, 59 carbon % on a bone dry basis, 60 carbon % on abone dry basis, 61 carbon % on a bone dry basis, 62 carbon % on a bonedry basis, 63 carbon % on a bone dry basis, 64 carbon % on a bone drybasis, 65 carbon % on a bone dry basis, or any amount therebetween.

As disclosed above, the amount of combustible liquid 12 absorbed andretained within torrefied densified biomass 30 may vary depending on oneor more factors exemplified by the duration of the torrefaction process,submersion of densified biomass 20 within the combustible liquid 12, thetemperature of the combustible liquid 12, the physico-chemicalproperties of the starting feedstock, the amount of the startingfeedstock, and the type of combustible liquid 12 used, amongst otherfactors. Consequently, the heat energy value of torrefied densifiedbiomass 30 and any other physico-chemical property of the torrefieddensified biomass 30, such as the carbon content, or the hydrophobicnature of the torrefied densified biomass 30, may also be tailored byadjusting the one or more variables such as the duration of thetorrefaction process, submersion of densified biomass 20 withincombustible liquid 12, the temperature of the combustible liquid 12, theproperties of the starting feedstock, the amount of the startingfeedstock, and the type of combustible liquid 12 used, amongst otherfactors.

EXAMPLES

The following examples are provided to enable a better understanding ofthe disclosure described herein.

Example 1 Materials and Methods

In this example, a small test unit was designed for testing purposes.The test unit consisted of: a small container for holding a combustibleliquid, such as vegetable oil; a gas burner, on which to place the smallcontainer; and a wire basket with a contour of the small container, suchthat the wire basket fit within the inner walls of the small container.In addition, a small scale capable of measuring up to 10 kgs in 0.001 kgincrements and a thermocouple and temperature gauge was used for weightand temperature calculations, respectively.

For this example, 10 kilograms of densified softwood pellets made from ablend of spruce, pine and fir were tested. The 10 kilograms were dividedinto 1 kilogram samples (using the small scale for measuring), and 1sample was set aside for testing purposes. As an initial step, the smallcontainer was placed on a scale and the net weight of the empty smallcontainer was measured. Vegetable oil was then poured into the smallcontainer and the total weight of the small container plus vegetable oilwas measured, thereby providing a net weight for the vegetable oil. Onekilogram of unheated oil was set aside for additional measurements.

Once the measurements of the vegetable oil were complete, the gas burnerwas turned on to a temperature of about 270° C., and the temperature ofthe vegetable oil in the small container was monitored using thethermocouple and temperature gauge. After the temperature of thevegetable oil was stabilized at about 260° C. to about 270° C., a 1-Kgsample of densified wood pellets was loaded into the wire strainerbasket and submerged in the heated vegetable oil in the small containerfor about 5 minutes. The wire strainer basket with the densified woodpellets contained therein was then removed from the vegetable oil in thesmall container, and allowed to drain and drip dry over the smallcontainer for 5 minutes. The torrefied densified biomass was retrievedfrom the wire strainer basket and its weight measured, withoutsubmersing in a cold water, to avoid any water absorption by thetorrefied densified biomass and contamination of the results. The netweight loss or gain of the sample was then calculated by comparing tothe starting weight of the densified wood pellets, on a dry basis. Thenet weight of the used oil was also measured by measuring the smallcontainer containing the used oil and subtracting the weight of thesmall container. Oil loss by absorption and mass loss of pellets wascalculated. This process was repeated another 8 times, each with a 1kilogram sample of densified wood pellets. The total weight of the smallcontainer containing the oil was measured prior to each experiment. Onekilogram of the used vegetable oil in the small container was collectedfor additional testing purposes.

The resulting torrefied densified biomass from all 9 test experimentswere collected and mixed together to form a sample batch. One kilogramof the sample batch was collected for testing.

Results:

The results from two sample batches prepared according to the processdescribed for Example 1 are shown in Table 1. The test results indicatedthat with about 5 minutes in a vegetable oil heated to about 260° C. toabout 270° C., densified wood pellets increased in weight by an averageof about 10% and increased in BTU value by an average of 15%. Inaddition, the torrefied wood pellets were found to be hydrophobic and tohave increased grindability (i.e., high Hardgrove Grindability Index) ascompared to untorrefied wood pellets. “Hardgrove Grindability Index”(“HGI”) is a measure for grindability of coal. Grindability is indicatedusing the unit ° H, for example, “40° H” or “55° H.” A higher HGI valueindicates a more easily pulverized or more grindable product.

As shown in Table 1 below, the lower heating value (LHV) of two samplebatches of torrefied pellets obtained from the process were 23.11 and22.76 GJ/ton, respectively. This represents an increase in LHV ofapproximately 14.8% for sample 1 and approximately 16.1% for sample 2.Those skilled in the art will know that an average LHV for wood pelletfuel ranges from a low of 18.14 GJ/ton to a high of 19.72 GJ/ton, makingtorrefied wood pellets of the disclosed process to be approximately17.5% higher in heat value compared to good quality biofuel.

TABLE 1 Starting Densified Wood Torrefied Wood Pellet Torrefied WoodPellet Pellet #1 #1 #2 As Received As Received As Received MeasurementsBasis Dry Basis Basis Dry Basis Basis Dry Basis Weight 1 kg 1 kg 1 kg %Moisture* 7.00 0 2.78 0 0.59 0 Calorific Value (Gross) Btu/lb 8336 89639786 10066 9934 9993 Kcal/kg 4631 4979 5437 5592 5519 5552 GJ/ton 19.3920.85 22.76 23.41 23.11 23.24 % Carbon 55.46 55.79 % Hydrogen 6.58 6.62(excludes H in 36.92 moisture) % Nitrogen 0.09 0.09 % Sulphur 0.02 0.02% Ash 0.56 0.56 % Oxygen 36.70 36.92 % Hydrogen 6.65 — (includes H inmoisture) *“% Moisture” for the “Torrefied Wood Pellets” refers to theamount of water in the torrefied wood pellets immediately after thetorrefaction process (i.e., after drip drying for 5 minutes). “StartingDensified Wood Pellet” is the sample that was initially set aside fortesting purposes.

Example 2 Materials and Methods

In this example, a coastal hemlock briquette was quartered and eachquarter was used for testing. Three of the quarters were used in thetorrefaction process and one quarter was set aside. The initial weightof the quartered briquettes used in the torrefaction process is set outin Table 2 below.

The small test unit, as described above for Example 1, was used in thisexample. As an initial step, the small container was placed on a scaleand the net weight of the empty small container was measured. Vegetableoil was then poured into the small container and the total weight of thesmall container plus vegetable oil was measured, thereby providing a netweight for the vegetable oil. One kilogram of unheated oil was set asidefor additional measurements.

After the measurements of the vegetable oil were complete, the gasburner was turned on to a temperature of about 260° C., and thetemperature of the vegetable oil in the small container was monitored.After the temperature of the vegetable oil was stabilized at about 260°C., a quarter briquette sample was loaded into the wire strainer basketand submerged in the heated vegetable oil in the deep fryer for about7.5 minutes. The wire strainer basket with the quarter briquette samplecontained therein was then removed from the vegetable oil in the smallcontainer and allowed to drain over the deep fryer for 5 minutes. Thetorrefied densified biomass was then retrieved from the wire strainerbasket and its weight measured, without submersing in a cold water, toavoid any water absorption by the torrefied densified biomass andcontamination of the results. The net weight loss or gain of the samplewas then calculated by comparing to the starting weight of the densifiedwood pellets, on a dry basis. The net weight of the used oil was alsomeasured by measuring the small container containing the used oil andsubtracting the weight of the small container. Oil loss by absorptionand mass loss of pellets was calculated. This process was then repeatedanother 2 times for the other 2 quarter briquette samples, with theexception that 1 quarter briquette was torrefied for about 10 minutes,and the other for about 15 minutes. The total weight of the smallcontainer containing the oil was measured prior to each experiment. Onekilogram of the used vegetable oil in the small container was collectedfor additional testing purposes. The resulting torrefied densifiedbiomass from each experiment was collected for testing.

Results:

The results for Example 2 are shown in Table 2. The test resultsindicated that all quarter briquette samples increased in weight, onaverage, by about 10% as compared to the original weight of therespective quarter briquette, representing the approximate amount of oilabsorbed by the samples. In addition, the torrefied wood pellets werefound to be hydrophobic and to have increased grindability (i.e., highHardgrove scale score) as compared to untorrefied wood pellets.

TABLE 2 Quartered Briquettes Experiment Sample 1 Sample 2 Sample 3Starting Weight (g) 139.85 140.85 149.60 Finished Weight (g) 156.40155.25 165.75 Net Increase in Weight (%) 10.58% 9.28% 9.74% StartingTemp. of Oil (° C.) 222.00 269.00 266.00 Ending Temp. of Oil (° C.)266.00 270.00 267.00 Retention Time in Oil (mins) 15.00 7.50 10.00

Example 3 Materials and Methods

In this example, 2 1-Kg samples of densified softwood pellets made froma blend of spruce, pine and fir were tested in the small test unitdescribed above in Example 1.

As an initial step, the small container was placed on a scale and thenet weight of the empty small container was measured. Vegetable oil wasthen poured into the small container and the total weight of the smallcontainer plus vegetable oil was measured, thereby providing a netweight for the vegetable oil. One kilogram of unheated oil was set asidefor additional measurements.

After the measurements of the vegetable oil were complete, the gasburner was turned on to a temperature of about 250° C. to about 260° C.,and the temperature of the vegetable oil in the small container wasmonitored. After the temperature of the vegetable oil was stabilized atabout 250° C. to about 260° C., a 1-kilogram sample of densified woodpellets was loaded into the wire strainer basket and submerged in theheated vegetable oil in the small container for about 20 minutes for thefirst sample. The wire strainer basket with the densified wood pelletscontained therein was then removed from the vegetable oil in the smallcontainer and allowed to drain over the deep fryer for 5 minutes. Thetorrefied densified biomass was then retrieved from the wire strainerbasket and its weight measured, without submersing in a cold water bath,to avoid any water absorption by the torrefied densified biomass andcontamination of the results. The net weight loss or gain of the samplewas then calculated by comparing to the starting weight of the densifiedwood pellets, on a dry basis. The net weight of the used oil was alsomeasured by measuring the small container containing the used oil andsubtracting the weight of the small container. Oil loss by absorptionand mass loss of pellets was calculated.

After the above process, the second 1-kg sample was loaded into the wirestrainer basket and submerged in the heated vegetable oil in the smallcontainer for about 30 minutes. The wire strainer basket with thedensified wood pellets contained therein was then removed from the smallcontainer and allowed to drain over the deep fryer for 5 minutes. Thenet weight loss or gain of the sample was then calculated by comparingto the starting weight of the densified wood pellets, on a dry basis.The net weight of the used oil was also measured by measuring the smallcontainer containing the used oil and subtracting the weight of thesmall container. Oil loss by absorption and mass loss of pellets wascalculated. One kilogram of the used vegetable oil in the deep fryer wascollected for additional testing purposes.

Results:

It was found that with 20 minutes in a vegetable oil heated to about260° C. to about 270° C., torrefied pellets had a net loss of weight ofabout 2.20%. With 30 minutes in heated vegetable oil, it was found thattorrefied pellets had a net weight loss of about 6.16%. In addition, thetorrefied wood pellets were hydrophobic and had increased grindability(i.e., high Hardgrove scale score) as compared to untorrefied woodpellets.

Without wishing to be bound by theory, it is thought that some oilabsorption occurs during the first few minutes of torrefaction, whichmay result in a net increase in weight of the biomass. Following thefirst few minutes, the biomass is increasingly torrefied, therebyexpelling VOCs and losing weight, resulting in a torrefied densifiedbiomass that has a net weight loss as compared to the initial startingmaterial.

Example 4 Materials and Methods

In this example, 4 different samples of densified softwood pellets madefrom a blend of spruce, pine and fir, each weighing about 0.5 kg, weretested using the small test unit described in Example 1. Vegetable oilwas heated to 220° C. to about 240° C. in the small container. Theweight of the small container was measured before it was filled with oiland after it was filled with oil to determine the weight of the oilprior to the torrefaction process. One of the 4 different samples wassubmerged in the oil for a pre-determined amount of time, and thenallowed to drip dry over the small container for about 5 minutes. Thesmall container containing the oil was measured again following thetorrefaction process to determine the amount of oil absorbed by thesample. This procedure was repeated for the three other samples.

Results

The results indicated that there was less absorption with more time inthe heated oil, as described above in Example 3. As shown in Table 3below, sample 1, which was torrefied for about 10 minutes in the hotvegetable oil, showed about 9.6% oil absorption, and sample 2, which wastorrefied for about 15 minutes in the hot vegetable oil, showed about6.7% oil absorption.

TABLE 3 Oil Absorption During Torrefaction Sample 1 Sample 2 SampleWeight - at start 0.5 0.5 Moisture Content*    4%    4% Sample Weight -at start; bone dry basis 0.4808 0.4808 Sample Weight - at end 0.45 0.474Process Time 15 10 Change in Weight of Sample   −6%   −1% Oil Weight -at start 2.968 2.926 Oil Weight - at end 2.936 2.88 % Absorption of Oilby Sample 6.6556% 9.5674% (bone dry basis starting weight) *“MoistureContent” refers to the amount of water (in %) in the torrefied woodpellets immediately after the torrefaction process (i.e., after dripdrying for 5 minutes).

Example 5 Materials and Methods

In this example, 4 different samples of densified softwood pellets madefrom a blend of spruce, pine and fir were tested, with each samplehaving a starting weight of 250 grams (0.250 kg). Each sample was testedusing the method as described above in Example 1 and the temperature,time and weight parameters as specified below in Table 4.

Results

The results indicated that the rate of absorption of the oil by thepellets varied over time. As shown in Table 4 below, sample 1, which wastorrefied for about 15 minutes in the hot vegetable oil, showed about14.31% oil absorption per mass input of bone dry pellets; sample 2,which was torrefied for about 30 minutes in the hot vegetable oil,showed about 14.00% oil absorption per mass input of bone dry pellets;sample 3, which was torrefied for about 45 minutes in the hot vegetableoil, showed about 13.88% oil absorption per mass input of bone drypellets; and sample 4, which was torrefied for about 60 minutes in thehot vegetable oil, showed about 11.87% oil absorption per mass input ofbone dry pellets.

As shown in FIG. 7, the oil absorption initially occurred at a higherrate during the first few minutes of torrefaction, after which the rateof absorption decreased and then remained at a constant rate for aperiod of time. As the torrefaction period progressed further, the rateof absorption stopped and then showed negative values indicating thatoil was expelled from the torrefied biomass during the extended periodsof torrefaction. In this example, the highest rate of absorptionoccurred during the first 15 minutes of torrefaction after which, therate of absorption of oil slowed and then remained at a constant ratethrough 45 minutes of torrefaction, after which time, it appears thatthe densified biomass began expelling oil previously absorbed by thedensified biomass.

FIG. 7 also shows that the heat value of the torrefied pellets followingthe torrefaction process increased substantially between 0 and 15minutes of the torrefaction process, then to increased slowly and fairlyconsistently between 15 minutes and 45 minutes of torrefaction, andeventually began to decrease after 45 minutes of torrefaction. The “heatvalue of samples—at end” in Table 4 and “heat value of finished product”in FIG. 7 is the total of the torrefied biomass plus the absorbed oil.Accordingly, the results of this example suggest that as pelletedbiomass torrefies, the biomass expels oil (less oil in the finishedproduct means less heat value in the finished product derived from oil).Since there is a net gain in heat value of the torrefied pellets overthe long term, even with the expulsion of oil, the biomass itself isgaining heat value during the process and it is not simply due to oilabsorption.

TABLE 4 Oil Absorption and Heat Value for Different Submersion Times inCanola Oil Heated to 270° C. Sample 1 Sample 2 Sample 3 Sample 4Submersion time 15 30 45 60 (minutes) Sample Weight - at start 250.00250.20 250.80 250.45 (g) Moisture content (%) 1.82 1.82 1.82 1.82 SampleWeight - at start; 245.45 245.65 246.24 245.89 bone dry basis (g) SampleWeight - at 247.5 242.2 236.15 233.5 end (g) Oil Weight - at start (g)650 612.4 572.4 651.7 Oil Weight - at end (g) 612.4 573.35 531.7 612.6Gross Oil Used (g) 37.6 39.05 40.7 39.1 Oil Evaporation (g) 2.47 4.656.52 9.90 Net Oil Absorbed (g) 35.13 34.40 34.18 29.20 % Absorption ofOil 14.31 14.00 13.88 11.87 by Sample (bone dry basis starting weight)Heat Value of Samples - 18.00 18.00 18.00 18.00 at start (GJ/T @ 5% MC)Heat Value of Samples - 24.10 24.56 24.85 24.75 at end (GJ/T) *“MoistureContent” refers to the amount of water (in %) in the torrefied woodpellets immediately after the torrefaction process (i.e., after dripdrying for 5 minutes).

Example 6 Materials and Methods

In this example, 20 kilograms of densified softwood pellets made from ablend of spruce, pine and fir (SPF wood pellets) were tested. The 20kilograms were divided into 1 kilogram samples, and all 20 of the 1kilogram samples were tested using the method as to described above inExample 1 for a specific temperature (i.e., either 240, 245, 250, 255,250, 265 or 270° C.) and for a specific submersion time (i.e., either10, 15, 20, 25 or 30 minutes) at each temperature, with the exceptionthat a PITCO® commercial deep fryer was used for the process (ratherthan a small container with a gas burner). In addition, each sample wascooled in a water bath following the torrefaction process for 5 minutes,then removed from the cold water bath and allowed to drain for 5 minutesbefore collecting the sample in a large tub. The method was repeated forthe 20 1-kg samples for each different temperature and submersion timecondition. Accordingly, for each temperature and submersion timecombination, the method was repeated 20 times with a 1-kg sample eachtime. In addition, 10 1-kg samples were tested using the method asdescribed above in Example 1 at 280° C. for 30 minutes and 6 1-kgsamples were tested using the method as described above in Example 1 at290° C. for 30 minutes; that is, the method was repeated 10 times forthe temperature-time combination of 280° C. for 30 minutes, and themethod was repeated 6 times for the temperature-time combination of 290°C. for 30 minutes, and the results for each temperature-time combinationwere averaged.

The resulting torrefied densified biomass from the different testexperiments for each temperature-time condition were collected and mixedtogether to form a sample batch. One kilogram of the sample batch wascollected for testing. The resulting 1-kg sample batch was to analyzedto determine the heat values of the torrefied pellets after eachtemperature-time condition.

Results

The data for this Example 6 are shown in Tables 5-13 and reflected inFIGS. 8 and 9. This Example 6 substantiates the findings in Example 5(Table 4 and FIG. 7). The results indicated that thesubmersion/retention time in the heated canola oil and the temperatureof the heated oil substantially correlated with the heat value of thetorrefied wood pellet at the end of the process. As shown in Tables 5-13below, generally, the higher the temperature of the canola oil and thelonger the time retained in the heated canola oil, the greater the heatvalue of the torrefied pellets following the torrefaction process.

The highest heat energy value was obtained when densified pellets weresubmersed in 290° C. canola oil for 30 minutes (26.04 GJ/t on a bone drybasis) and the lowest heat energy value was obtained when densifiedpellets were submersed in 240° C. canola oil for 10 minutes (22.78 GJ/ton a bone dry basis). All heat energy values for the torrefied pelletswere greater than the heat energy value calculated for densified biomassthat was not torrefied (i.e., 20.49 GJ/t on a bone dry basis).Torrefying pellets at 250° C. produced a slightly higher heat energyvalue than when torrefying pellets at 255° C. at every time pointmeasured. Moreover, a submersion time of 20 minutes produced the highestheat energy value when using canola oil at a temperature of 265° C. Thisdata, therefore, indicated that the torrefaction process may be tailoredas desired by varying the temperature of the canola oil and the timesubmersed in the heated oil.

TABLE 5 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 240° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 6.05 04.92 0 % Ash 0.42 0.44 0.38 0.41 0.37 0.39 % Volatile 79.99 84.79 79.8184.95 81.19 85.39 Matter % Fixed 13.93 14.77 13.76 14.64 13.52 14.22Carbon % Sulphur 0.03 0.04 0.02 0.02 0.02 0.02 Calorific Value (Gross)Btu/lb 8309 8807 9202 9794 9437 9925 Kcal/kg 4616 4893 5112 5441 52435514 GJ/T 19.33 20.49 21.4 22.78 21.95 23.09 % Carbon 47.76 50.62 51.4854.8 52.32 55.03 % Nitrogen 0.068 0.073 0.032 0.034 0.019 0.020 % Oxygen40.36 42.78 35.75 38.05 35.97 37.83 Torrefusion Torrefusion Torrefusionfor 20 mins. for 25 mins. for 30 mins. Wet Dry Wet Dry Wet DryMeasurements Basis Basis Basis Basis Basis Basis Weight 1 kg 1 kg 1 kg %Moisture* 5.2 0 4.12 0 3.31 0 % Ash 0.34 0.36 0.37 0.38 0.35 0.36 %Volatile 80.26 84.66 81.28 84.77 81.4 84.19 Matter % Fixed 14.2 14.9814.23 14.85 14.94 15.45 Carbon % Sulphur 0.01 0.01 0.01 0.01 0.01 0.01Calorific Value (Gross) Btu/lb 9505 10026 9646 10060 9791 10127 Kcal/kg5281 5570 5359 55.89 5440 5626 GJ/T 22.11 23.32 22.44 23.4 22.77 23.55 %Carbon 52.65 55.53 53.19 55.47 53.85 55.69 % Nitrogen 0.035 0.037 0.0360.038 0.044 0.045 % Oxygen 35.36 37.31 35.80 37.35 35.91 37.13 *“%Moisture” with respect to the “Torrefied Wood Pellets” on a “Wet Basis”refers to the amount of water (in %) in the sample following cooling inthe water bath for 5 minutes and then draining for 5 minutes, asdescribed in the Methods.

TABLE 6 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 245° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 7.28 06.76 0 % Ash 0.42 0.44 0.32 0.34 0.35 0.37 % Volatile 79.99 84.79 79.185.31 78.77 84.48 Matter % Fixed 13.93 14.77 13.3 14.35 14.12 15.15Carbon % Sulphur 0.03 0.04 0.01 0.01 0.01 0.01 Calorific Value (Gross)Btu/lb 8309 8807 9260 9987 9360 10039 Kcal/kg 4616 4893 5145 5548 52005577 GJ/T 19.33 20.49 21.54 23.23 21.77 23.35 % Carbon 47.76 50.62 51.0155.01 51.69 55.44 % Nitrogen 0.068 0.073 0.040 0.043 0.040 0.043 %Oxygen 40.36 42.78 35.10 37.87 34.84 37.37 Torrefusion TorrefusionTorrefusion for 20 mins. for 25 mins. for 30 mins. Wet Dry Wet Dry WetDry Measurements Basis Basis Basis Basis Basis Basis Weight 1 kg 1 kg 1kg % Moisture* 4.9 0 5.17 0 4.87 0 % Ash 0.41 0.43 0.41 0.43 0.39 0.41 %Volatile 80.82 84.98 79.91 84.27 80.1 84.2 Matter % Fixed 13.87 14.5914.51 15.3 14.64 15.39 Carbon % Sulphur 0.01 0.01 0.02 0.02 0.02 0.02Calorific Value (Gross) Btu/lb 9583 10076 9619 10144 9702 10198 Kcal/kg5324 5598 5344 5635 5390 5666 GJ/T 22.29 23.44 22.37 23.59 22.57 23.72 %Carbon 52.99 55.72 52.99 55.88 53.04 55.75 % Nitrogen 0.037 0.039 0.0360.038 0.032 0.033 % Oxygen 35.32 37.14 34.99 36.90 35.28 37.09 *“%Moisture” with respect to the “Torrefied Wood Pellets” on a “Wet Basis”refers to the amount of water (in %) in the sample following cooling inthe water bath for 5 minutes and then draining for 5 minutes, asdescribed in the Methods.

TABLE 7 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 250° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 5.83 06.42 0 % Ash 0.42 0.44 0.36 0.38 0.38 0.41 % Volatile 79.99 84.79 79.4384.35 79.35 84.8 Matter % Fixed 13.93 14.77 14.38 15.27 13.85 14.79Carbon % Sulphur 0.03 0.04 0.02 0.02 0.02 0.02 Calorific Value (Gross)Btu/lb 8309 8807 9411 9994 9459 10107 Kcal/kg 4616 4893 5228 5552 52555615 GJ/T 19.33 20.49 21.89 23.25 22 23.51 % Carbon 47.76 50.62 51.6754.87 51.96 55.52 % Nitrogen 0.068 0.073 0.040 0.042 0.038 0.041 %Oxygen 40.36 42.78 35.79 38.01 34.89 37.29 Torrefusion TorrefusionTorrefusion for 20 mins. for 25 mins. for 30 mins. Wet Dry Wet Dry WetDry Measurements Basis Basis Basis Basis Basis Basis Weight 1 kg 1 kg 1kg % Moisture* 7.93 0 5.32 0 4.91 0 % Ash 0.4 0.43 0.4 0.42 0.41 0.43 %Volatile 78.03 84.75 79.89 84.39 79.71 83.83 Matter % Fixed 13.64 14.8214.39 15.19 14.97 15.74 Carbon % Sulphur 0.02 0.02 0.02 0.02 0.01 0.01Calorific Value (Gross) Btu/lb 9447 10261 9735 10283 9849 10358 Kcal/kg5248 5701 5408 5713 5472 5754 GJ/T 21.97 23.87 22.64 23.92 22.91 24.09 %Carbon 51.48 55.91 52.93 55.91 53.61 56.38 % Nitrogen 0.034 0.037 0.0340.036 0.036 0.038 % Oxygen 33.93 36.85 34.90 36.85 34.59 36.38 *“%Moisture” with respect to the “Torrefied Wood Pellets” on a “Wet Basis”refers to the amount of water (in %) in the sample following cooling inthe water bath for 5 minutes and then draining for 5 minutes, asdescribed in the Methods.

TABLE 8 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 255° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 8.63 09.5 0 % Ash 0.42 0.44 0.39 0.42 0.37 0.41 % Volatile 79.99 84.79 77.8785.23 76.01 83.99 Matter % Sulphur 0.03 0.04 0.01 0.01 0.01 0.02Calorific Value (Gross) Btu/lb 8309 8807 9130 9992 9059 10011 Kcal/kg4616 4893 5072 5551 5033 5561 GJ/T 19.33 20.49 2124 23.24 21.07 23.28 %Carbon 47.76 50.62 51.14 55.97 51.07 56.43 % Nitrogen 0.068 0.073 0.0660.073 0.067 0.074 % Oxygen 40.36 42.78 33.58 36.77 32.83 36.28Torrefusion Torrefusion Torrefusion for 20 mins. for 25 mins. for 30mins. Wet Dry Wet Dry Wet Dry Measurements Basis Basis Basis Basis BasisBasis Weight 1 kg 1 kg 1 kg % Moisture* 7.17 0 6.86 0 6.77 0 % Ash 0.440.48 0.51 0.55 0.41 0.44 % Volatile 78.75 84.84 78.09 83.84 78.49 84.2Matter % Sulphur 0.02 0.02 0.01 0.01 0.02 0.03 Calorific Value (Gross)Btu/lb 9437 10166 9447 10143 9564 10259 Kcal/kg 5243 5648 5248 5635 53135700 GJ/T 21.95 23.65 21.97 23.59 22.25 23.86 % Carbon 52.63 56.69 52.9656.87 53.5 57.38 % Nitrogen 0.063 0.067 0.061 0.065 0.062 0.067 % Oxygen33.37 35.94 33.30 35.73 32.86 35.23 *“% Moisture” with respect to the“Torrefied Wood Pellets” on a “Wet Basis” refers to the amount of water(in %) in the sample following cooling in the water bath for 5 minutesand then draining for 5 minutes, as described in the Methods.

TABLE 9 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 260° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 10.01 07.62 0 % Ash 0.42 0.44 0.39 0.44 0.39 0.42 % Volatile 79.99 84.79 76.0684.52 78.25 84.7 Matter % Sulphur 0.03 0.04 0.01 0.01 0.01 0.01Calorific Value (Gross) Btu/lb 8309 8807 8989 9989 9475 10256 Kcal/kg4616 4893 4994 5550 5264 5698 GJ/T 19.33 20.49 20.91 23.24 22.04 23.86 %Carbon 47.76 50.62 50.81 56.47 52.5 56.83 % Nitrogen 0.068 0.073 0.0680.075 0.064 0.069 % Oxygen 40.36 42.78 32.59 36.19 33.13 35.87Torrefusion Torrefusion Torrefusion for 20 mins. for 25 mins. for 30mins. Wet Dry Wet Dry Wet Dry Measurements Basis Basis Basis Basis BasisBasis Weight 1 kg 1 kg 1 kg % Moisture* 9.13 0 6.92 0 6.59 0 % Ash 0.370.41 0.39 0.42 0.4 0.43 % Volatile 75.83 83.44 77.91 83.7 77.42 82.89Matter % Sulphur 0.01 0.01 0.02 0.02 0.02 0.03 Calorific Value (Gross)Btu/lb 9376 10318 9677 10397 9771 10461 Kcal/kg 5209 5732 5376 5776 54285812 GJ/T 21.81 24 22.51 24.18 22.73 24.33 % Carbon 51.92 57.14 53.4257.39 53.87 57.68 % Nitrogen 0.063 0.070 0.069 0.074 0.058 0.062 %Oxygen 32.34 35.58 32.86 35.31 32.71 35.00 *“% Moisture” with respect tothe “Torrefied Wood Pellets” on a “Wet Basis” refers to the amount ofwater (in %) in the sample following cooling in the water bath for 5minutes and then draining for 5 minutes, as described in the Methods.

TABLE 10 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 265° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 8.35 09.44 0 % Ash 0.42 0.44 0.38 0.41 0.39 0.43 % Volatile 79.99 84.79 77.4584.51 75.58 83.46 Matter % Sulphur 0.03 0.04 0.02 0.02 0.01 0.01Calorific Value (Gross) Btu/lb 8309 8807 9341 10193 9326 10298 Kcal/kg4616 4893 5190 5663 5181 5721 GJ/T 19.33 20.49 21.73 23.71 21.69 23.95 %Carbon 47.76 50.62 51.67 56.38 51.66 57.05 % Nitrogen 0.068 0.073 0.0680.074 0.064 0.071 % Oxygen 40.36 42.78 33.35 36.39 32.34 35.71Torrefusion Torrefusion Torrefusion for 20 mins. for 25 mins. for 30mins. Wet Dry Wet Dry Wet Dry Measurements Basis Basis Basis Basis BasisBasis Weight 1 kg 1 kg 1 kg % Moisture* 7.53 0 7.06 0 6.76 0 % Ash 0.370.4 0.38 0.41 0.4 0.43 % Volatile 77.2 83.49 76.74 82.57 77.25 82.86Matter % Sulphur 0.01 0.01 0.01 0.01 0.01 0.01 Calorific Value (Gross)Btu/lb 9759 10554 9763 10504 9823 10535 Kcal/kg 5422 5863 5424 5836 54575853 GJ/T 22.7 24.55 22.71 24.43 22.85 24.51 % Carbon 53.85 5824 53.8757.96 54.33 58.27 % Nitrogen 0.063 0.068 0.062 0.067 0.053 0.057 %Oxygen 31.88 34.46 32.31 34.76 32.10 34.42 *“% Moisture” with respect tothe “Torrefied Wood Pellets” on a “Wet Basis” refers to the amount ofwater (in %) in the sample following cooling in the water bath for 5minutes and then draining for 5 minutes, as described in the Methods.

TABLE 11 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 270° C. Before Torrefusion Torrefusion Torrefusion for 10mins. for 15 mins. Wet Dry Wet Dry Wet Dry Measurements Basis BasisBasis Basis Basis Basis Weight 1 kg 1 kg 1 kg % Moisture* 5.66 0 9.36 010.12 0 % Ash 0.42 0.44 0.34 0.38 0.36 0.4 % Volatile 79.99 84.79 76.484.3 75.3 83.77 Matter % Fixed 13.93 14.77 13.90 15.32 14.22 15.83Carbon % Sulphur 0.03 0.04 0.03 0.03 0.03 0.03 Calorific Value (Gross)Btu/lb 8309 8807 9347 10313 9347 10399 Kcal/kg 4616 4893 5193 5729 51935777 GJ/T 19.33 20.49 21.74 23.99 21.74 24.19 % Carbon 47.76 50.62 51.7457.08 51.82 57.65 % Nitrogen 0.068 0.073 0.149 0.164 0.139 0.155 %Oxygen 40.36 42.78 32.31 35.66 31.47 35.03 Torrefusion TorrefusionTorrefusion for 20 mins. for 25 mins. for 30 mins. Wet Dry Wet Dry WetDry Measurements Basis Basis Basis Basis Basis Basis Weight 1 kg 1 kg 1kg % Moisture* 8.26 0 7.28 0 7.2 0 % Ash 0.41 0.44 0.38 0.41 0.38 0.41 %Volatile 75.32 82.11 77.14 83.2 76.3 82.23 Matter % Fixed — — 15.2016.39 16.12 17.36 Carbon % Sulphur 0.01 0.01 0.03 0.03 0.03 0.03Calorific Value (Gross) Btu/lb 9623 10490 9858 10631 9918 10688 Kcal/kg5346 5828 5477 5906 5510 5938 GJ/T 22.38 24.4 22.93 24.73 23.07 24.86 %Carbon 53.39 58.19 54.39 58.66 54.85 59.11 % Nitrogen 0.068 0.074 0.1340.145 0.134 0.144 % Oxygen 31.64 34.51 31.50 33.98 31.09 33.50 *“%Moisture” with respect to the “Torrefied Wood Pellets” on a “Wet Basis”refers to the amount of water (in %) in the sample following cooling inthe water bath for 5 minutes and then draining for 5 minutes, asdescribed in the Methods.

TABLE 12 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 280° C. Before Torrefusion Torrefusion for 30 mins.Measurements Wet Basis Dry Basis Wet Basis Dry Basis Weight 1 kg 1 kg %Moisture* 5.66 0 9.05 0 % Ash 0.42 0.44 0.41 0.45 % Volatile Matter79.99 84.79 73.75 81.09 % Fixed Carbon 13.93 14.77 16.79 18.46 % Sulphur0.03 0.04 0.03 0.03 Calorific Value (Gross) Btu/lb 8309 8807 9913 10900Kcal/kg 4616 4893 5507 6056 GJ/T 19.33 20.49 23.06 25.35 % Carbon 47.7650.62 54.62 60.06 % Nitrogen 0.068 0.073 0.138 0.152 % Oxygen 40.3642.78 29.60 32.54 *“% Moisture” with respect to the “Torrefied WoodPellets” on a “Wet Basis” refers to the amount of water (in %) in thesample following cooling in the water bath for 5 minutes and thendraining for 5 minutes, as described in the Methods.

TABLE 13 Heat Value of Torrefied Wood Pellets Before and AfterTorrefusion at 290° C. Before Torrefusion Torrefusion for 30 mins.Measurements Wet Basis Dry Basis Wet Basis Dry Basis Weight 1 kg 1 kg %Moisture* 5.66 0 10.03 0 % Ash 0.42 0.44 0.43 0.47 % Volatile Matter79.99 84.79 71.15 79.08 % Fixed Carbon 13.93 14.77 18.39 20.45 % Sulphur0.03 0.04 0.03 0.03 Calorific Value (Gross) Btu/lb 8309 8807 10071 11194Kcal/kg 4616 4893 5595 6219 GJ/T 19.33 20.49 23.42 26.04 % Carbon 47.7650.62 55.91 62.15 % Nitrogen 0.068 0.073 0.143 0.159 % Oxygen 40.3642.78 27.31 30.35 *“% Moisture” with respect to the “Torrefied WoodPellets” on a “Wet Basis” refers to the amount of water (in %) in thesample following cooling in the water bath for 5 minutes and thendraining for 5 minutes, as described in the Methods.

Example 7 Materials and Methods

The same method as described in Example 6 was used in this example,including the different submersion times in the heated canola oil (i.e.,either 10, 15, 20, 25 or 30 minutes) and the different temperatures ofthe canola oil used in the process (i.e., either 240, 245, 250, 255,250, 265 or 270° C.; and submersing for 30 minutes at 280° C. or 290°C.).

In this example, the resulting data was analyzed to determine the carboncontent of the torrefied pellets after each temperature-timecombination.

Results

The data for this Example 7 are shown in Tables 5-13 above and in FIG.10. The results indicated that the carbon percentage of the torrefiedwood pellets at the end of the torrefaction process generally increasedwith an increase in submersion/retention time in heated canola oil andwith an increase in the temperature of the heated oil. As shown in FIG.10, there was a general upward trend in the carbon content of thetorrefied wood pellets with an increase in temperature of the canolaoil. There was also substantial correlation between carbon content andsubmersion time in heated oil.

The highest carbon content was obtained when the densified wood pelletswere submersed in 290° C. canola oil for 30 minutes (62.15 carbon % on abone dry basis) and the lowest carbon content was obtained when thedensified wood pellets were submersed in 240° C. canola oil for 10minutes (54.80 carbon % on a bone dry basis). The carbon content for alltorrefied pellets was greater than the carbon percentage calculated fordensified biomass that was not torrefied (i.e., 50.62 carbon % on a bonedry basis).

Example 8 Materials and Methods

The amount of evaporation of the different types of combustible liquidswere tested. Each combustible liquid was tested once using the followingevaporation test. The small test unit as described above for Example 1was used for this test. The small container was placed on the scale andthe net weight of the empty small container was measured. A volume ofoil was measured out and poured into the small container and a lidplaced on top of the small container. The gas burner was then turned onto 270° C., and the temperature of the oil was monitored. Once thedesired temperature of 270° C. was reached, the small container with thevegetable oil was removed from the gas burner and the small containerwith the vegetable oil was calculated. The small container with thevegetable oil was then put back on the gas burner and allowed to heatfor 30 minutes at 270° C. The weight of the small container with thevegetable oil was measured after 30 minutes of heating and the reductionin weight caused by evaporation recorded.

The different combustible liquids tested were: canola oil, sunfloweroil, corn oil, peanut oil, bar and chain oil, 5W30 oil, automatictransmission fluid, hydraulic fluid AW32, gear oil 80W90, and paraffinwax.

Results

The results indicated that evaporation of each of the differentcombustible liquids after heating at 270° C. for 30 minutes wasnegligible. Accordingly, evaporation of the combustible liquids was nottaken into account when calculating oil absorption by torrefieddensified biomass following a torrefaction process.

Example 9 Materials and Methods

This Example 9 was performed in order to compare the oil absorption bydensified pellets when using canola oil as the combustible liquid versusparaffin wax as the combustible liquid.

In this example, densified softwood pellets made from a blend of spruce,pine and fir (SPF wood pellets) were tested. A 250 gram sample of SPFwood pellets was weighed out and a wire sieve for holding the densifiedmaterial was separately weighed. The sample of densified material wasthen loaded into the wire sieve and the total weight of the sieve plusdensified material was measured and then set aside for testing purposes.The small test unit described in Example 1 was used for this example. Asan initial step, the small container was placed on a scale and the netweight of the small container was measured. A volume of oil (eithercanola oil or paraffin wax) was measured out and poured into the smallcontainer and the total weight of the small container plus oil wasmeasured, thereby providing a net weight for the oil.

Once the measurements of the oil were complete, the gas burner wasturned on to a specific temperature (either 250° C., 260° C. or 270°C.), and the temperature of the oil was monitored.

After the temperature of the oil was stabilized at the desiredtemperature, the following weights were measured: (a) the weight of thesmall container plus the heated oil; (b) the weight of the smallcontainer plus the heated oil plus the lid for the small container plusa temperature probe inserted into the small container; and (c) theweight of the small container plus the heated oil plus the lid for thesmall container plus a temperature probe inserted into the smallcontainer plus the 250 gram sample of densified material loaded in thewire sieve and placed on top of the small container (i.e., not yetsubmerged in the small container).

Upon completion of the above measurements, the wire sieve containing thedensified material was submerged in the heated oil and the smallcontainer covered with a lid. The densified material was submerged inthe heated oil for a specific amount of time (either 15 or 30 minutes).After submersion for the desired time, the gas burner was turned off andthe total weight of the small container, oil, lid, temperature probe,sieve and densified material was measured (with the sieve and densifiedmaterial still submerged in the oil). The wire sieve with the densifiedmaterial contained therein was then removed from the small container andoil, and allowed to drain over the small container for about fiveminutes. The drained wire sieve with the densified material containedtherein was weighed, and the densified material was subsequently weighedseparately. With the sieve and densified material removed, the totalweight of the small container, oil, lid and temperature probe wasweighed and then the total weight of the small container plus oil wassubsequently weighed separately.

The bone dry weight of the torrefied pellets was then calculated (i.e.,to provide a bone dry basis for the torrefied pellets), and then thebone dry weight of the pellets was compared to the loss of oil and a %oil absorption calculated.

The above process was completed twice for each temperature, time and oilcombination (i.e., two test runs done for each different type of oilbeing tested at each different temperature and submersion time), witheach process starting with a 250 gram sample of densified pellets.

Results

As shown in FIG. 11, when canola oil was used as the combustible liquidfor the torrefaction process, oil absorption by the densified biomasstended to generally increase when the temperature of the canola oil wasincreased from 250° C. to 260° C., but then declined slightly whentorrefied at a temperature of 270° C. There also appeared to be ageneral decrease in weight of the torrefied densified biomass withincreased temperature; however, carrying out the torrefaction process at260° C. for 30 minutes caused an increase in weight (i.e., +11.48 gcompared to starting weight, which amounted to a weight of 249.35 g) ascompared to carrying out the process at 250° C. for 30 minutes (+8.53 gcompared to starting weight, which amounted to an end weight of 246.4g). This increase in weight corresponded with an increase in oilabsorption for this temperature-time condition (i.e., an oil absorptionof 21.02% per mass input of bone dry pellets at 260° C. for 30 minutes,as compared to an oil absorption of 16.65% at 250° C. for 30 minutes),which suggested that the weight increase is due to the increased oilabsorption when torrefying at 260° C. for 30 minutes. The slight declinein oil absorption when a temperature of 270° C. was used (i.e., 16.86%oil absorption at 15 minutes and 17.11% at 30 minutes) also correspondedto a decrease in the weight of the torrefied densified biomass at thistemperature (i.e., −1.28 g at 15 minutes and −5.47 g at 30 minutes),further suggesting that oil absorption is correlated with the weight ofthe resulting torrefied densified biomass. This data also correlatedwith the data obtained from Examples 3 and 5.

FIG. 12 shows that similar results were obtained when paraffin wax wasused as the combustible liquid. Oil absorption by the densified biomasstended to generally increase when the temperature of the paraffin waxwas increased from 250° C. to 260° C., but then declined when torrefiedat a temperature of 270° C. The rate of increase in the oil absorptionwas greater for paraffin wax than for canola oil when increasing thetemperature from 250° C. to 260° C. and when increasing the submersiontime at each temperature point. As with canola oil, there also appearedto be a general decrease in weight of the torrefied densified biomasswith increased temperature. However, there did not seem to be acorrelation between the weight of the torrefied densified biomass at theend of the process and the oil absorbed by the torrefied densifiedbiomass as seen with canola oil.

FIG. 13 and Tables 14 and 15 below illustrate that generally more canolaoil was lost during the torrefaction process when canola oil was used asthe combustible liquid. The amount of oil loss was generally similarwhen using either canola oil or paraffin wax, except when torrefying at250° C. The amount of paraffin wax lost when torrefying at 250° C. for15 minutes was significantly less with paraffin wax. Furthermore, therate of loss of oil between 15 minutes of torrefaction and 30 minutes oftorrefaction at 250° C. when paraffin wax was used as the combustibleliquid seemed to be significantly greater than when canola oil was used.

As shown in FIG. 14, when using canola oil as the combustible liquidrather than paraffin wax, the reduction in weight of the torrefiedpellet as compared to the starting biomass differed. For both, as shownin Tables 14 and 15 and described above, the weight of the torrefiedpellets generally tended to decrease with increased temperature.However, with canola oil, the weight of the torrefied pellets wasgreater than the starting densified pellets when the torrefactionprocess was carried out at 250° C. and 260° C. There was only areduction in weight as compared to the starting densified pellets whentorrefying at 270° C. With paraffin wax, the end weight of the torrefiedpellet was generally less than the starting weight of the densifiedpellet, except when torrefying at 250° C. for 15 minutes. Paraffin waxgenerally led to a greater reduction in weight at all time points andtemperatures. Without wishing to be bound by theory, these results maybe due to the biomass absorbing less paraffin wax during thetorrefaction process than when canola oil is used. Less absorption ofthe paraffin wax may be as a result of the longer molecular chain ofparaffin wax and perhaps a greater evaporation rate of paraffin wax.

TABLE 14 Canola Oil Absorption by Pellets and Weight Reduction ofPellets During Torrefaction at Different Temperatures and SubmersionTimes Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 SubmersionTime (mins.) 15 30 15 30 15 30 Temperature (° C.) 250 250 260 260 270270 Sample Weight - at start; 250.00 250.00 250.00 250.00 250.00 250.00wet basis (g) Moisture Content (%)* 4.85 4.85 4.85 4.85 4.85 4.85 SampleWeight - at start; 237.88 237.88 237.88 237.88 237.88 237.88 bone drybasis (g) Sample Weight - at end; 251.30 246.40 244.48 249.35 236.60232.40 bone dry basis (g) Change in Weight - bone dry +13.43 +8.53 +6.60+11.48 −1.28 −5.47 basis (g) Pot + Oil Weight - at start 2,390.202,350.75 2,355.40 2,359.20 2,352.90 2,346.70 (g) Pot + Oil Weight - atend (g) 2,356.20 2,311.15 2,318.10 2,309.20 2,312.80 2,306.00 Change inPot + Oil Weight −34.00 −39.60 −37.30 −50.00 −40.10 −40.70 (g) Reductionin Pellet Weight 5.64 3.58 2.78 4.82 −0.54 −2.30 Start to Finish (%) %Oil Absorption by Sample 14.29% 16.65% 15.68% 21.02% 16.86% 17.11%Including Evaporation (bone dry basis) *“Moisture Content” refers to theamount of water in the samples immediately after the torrefactionprocess (i.e., after drip drying for 5 minutes).

TABLE 15 Paraffin Wax Absorption by Pellets and Weight Reduction ofPellets During Torrefaction at Different Temperatures and SubmersionTimes Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 SubmersionTime (mins.) 15 30 15 30 15 30 Temperature (° C.) 250 250 260 260 270270 Sample Weight - at start; 250.00 250.00 250.00 250.00 250.00 250.00wet basis (g) Moisture Content (%)* 4.85 4.85 4.85 4.85 4.85 4.85 SampleWeight - at start; 237.88 237.88 237.88 237.88 237.88 237.88 bone drybasis (g) Sample Weight - at end; 242.60 234.95 231.40 230.75 219.15210.95 bone dry basis (g) Change in Weight - bone dry +4.72 −2.93 −6.47−7.13 −18.73 −26.93 basis (g) Pot + Oil Weight - at start 2,185.102,222.35 2,183.30 2,212.05 2,252.75 2,214.60 (g) Pot + Oil Weight - atend (g) 2,178.60 2,186.40 2,151.30 2,162.85 2,219.20 2,176.45 Change inPot + Oil Weight 6.50 35.95 32.00 49.20 33.55 38.15 (g) Reduction inPellet Weight 1.99 −1.23 −2.72 −3.00 −7.87 −11.32 Start to Finish (%) %Oil Absorption by Sample 3 15 13 21 14 16 Including Evaporation (bonedry basis) *“Moisture Content” refers to the amount of water in thesamples immediately after the torrefaction process (i.e., after dripdrying for 5 minutes).

Example 10 Materials and Methods

The torrefied pellets from Example 6, which proceeded through thetorrefaction process at different temperatures (240° C., 245° C., 250°C., 255° C., 260° C., 265° C., 270° C., 280° C. or 290° C.) fordifferent submersion times (10, 15, 20, 25 or 30 minutes), were testedto determine the hydrophobic nature of the torrefied pellets. To dothis, a 953.63 gram sample from each batch of processed torrefieddensified biomass corresponding to a specific temperature-time conditionwas measured out and submersed in water for two weeks (i.e., 14 days).Once removed from the water, the samples were allowed to drain in asieve for 5 minutes, and then each sample was weighed to measure thechange in weight of the sample. This measurement was compared to theweight of the water, and the amount of water absorbed by each sample wascalculated.

Results

The data in Table 16 indicated that as the temperature of thetorrefaction process increased (i.e., the temperature of the heatedcanola oil), the hydrophobic nature of the resulting product increased.This data is represented in FIGS. 15 and 16, which show that the amountof water absorbed by the torrefied densified pellets following thetorrefaction process correlated with the temperature of the torrefactionprocess. When torrefied at higher temperatures (such as 270° C., 280° C.or 290° C.) rather than at lower temperatures (such as 240° C.), theresulting torrefied densified pellets absorbed less water into thepellets.

The submersion time in the heated canola oil appeared to be lessmaterial to the hydrophobic nature of the resulting product; however,the results indicated that generally for shorter submersion times (e.g.,10 minutes), more water was absorbed by the resulting torrefieddensified pellets compared to when longer submersion times were used forthe torrefaction process (e.g., 30 minutes).

TABLE 16 Water Absorption Following Torrefaction Torrefaction ProcessGross Weight of Net Torrefied Water temperature time Weight of ContainerWeight of Sample Absorbed Sample (° C.) (minutes) Water (g) (g) Water(g) Weight (g) (g) 1 240 10 1,536.50 46.37 1490.13 953.63 536.50 2 24015 1,437.20 46.37 1390.83 953.63 437.20 3 240 20 1,397.50 46.37 1351.13953.63 397.50 4 240 25 1,391.50 46.37 1345.13 953.63 391.50 5 240 301,394.00 46.37 1347.63 953.63 394.00 6 245 10 1,448.35 46.37 1401.98953.63 448.35 7 245 15 1,377.20 46.37 1330.83 953.63 377.20 8 245 201,377.85 46.37 1331.48 953.63 377.85 9 245 25 1,336.45 46.37 1290.08953.63 336.45 10 245 30 1,335.70 46.37 1289.33 953.63 335.70 11 250 101,421.80 46.37 1375.43 953.63 421.80 12 250 15 1,337.90 46.37 1291.53953.63 337.90 13 250 20 1,305.20 46.37 1258.83 953.63 305.20 14 250 251,319.70 46.37 1273.33 953.63 319.70 15 250 30 1,285.55 46.37 1239.18953.63 285.55 16 255 10 1358.10 46.37 1311.73 953.63 358.10 17 255 151286.25 46.37 1239.88 953.63 286.25 18 255 20 1291.85 46.37 1245.48953.63 291.85 19 255 25 1260.05 46.37 1213.68 953.63 260.05 20 255 301243.35 46.37 1196.98 953.63 243.35 21 260 10 1294.50 46.37 1248.13953.63 294.50 22 260 15 1290.30 46.37 1243.93 953.63 290.30 23 260 201232.85 46.37 1186.48 953.63 232.85 24 260 25 1227.95 46.37 1181.58953.63 227.95 25 260 30 1223.95 46.37 1177.58 953.63 223.95 26 265 101281.10 46.37 1234.73 953.63 281.10 27 265 15 1224.85 46.37 1178.48953.63 224.85 28 265 20 1225.40 46.37 1179.03 953.63 225.40 29 265 251208.25 46.37 1161.88 953.63 208.25 30 265 30 1207.40 46.37 1161.03953.63 207.40 31 270 10 1236.80 46.37 1190.43 953.63 236.80 32 270 151184.40 46.37 1138.03 953.63 184.40 33 270 20 1192.30 46.37 1145.93953.63 192.30 34 270 25 1164.10 46.37 1117.73 953.63 164.10 35 270 301167.80 46.37 1121.43 953.63 167.80 36 280 30 1161.60 46.37 1115.23953.63 161.60 37 290 30 1149.90 46.37 1103.53 953.63 149.90

Example 11 Materials and Methods

In this example, both densified softwood pellets made from a blend ofspruce, pine and fir (SPF wood pellets) and densified hog fuel weretested. A 250 gram sample of either SPF wood pellets or densified hogfuel was weighed out and a wire sieve for holding the densified materialwas separately weighed. The sample of densified material was then loadedinto the wire sieve and the total weight of the sieve plus densifiedmaterial was measured and then set aside for testing purposes using thesmall test unit described in Example 1.

As an initial step, the small container was placed on a scale and thenet weight of the empty small container was measured. A volume of oil(one of the following: sunflower oil, corn oil, peanut oil, canola oil,bar and chain oil, 5W30 oil, automatic transmission fluid, hydraulicfluid AW32, gear oil 80W90, or paraffin wax) was measured out and pouredinto the small container and the total weight of the small containerplus oil was measured, thereby providing a net weight for the oil.

Once the measurements of the oil were complete, the gas burner wasturned on to the testing temperature of 270° C., and the temperature ofthe oil was monitored.

After the temperature of the oil was stabilized at 270° C., thefollowing weights were measured: (a) the weight of the small containerplus the heated oil; (b) the weight of the small container plus theheated oil plus the lid for the small container plus a temperature probeinserted into the small container; and (c) the weight of the smallcontainer plus the heated oil plus the lid for the small container plusa temperature probe inserted into the small container plus the 250 gramsample of densified material loaded in the wire sieve and placed on topof the small container (i.e., not yet submerged in the small container).

Upon completion of the above measurements, the wire sieve containing thedensified material was submerged in the heated oil and the smallcontainer covered with a lid. The densified material was submerged inthe heated oil for 30 minutes. After the 30 minute submersion time, thesmall container was turned off and the total weight of the smallcontainer, oil, lid, temperature probe, sieve and densified material wasmeasured (with the sieve and densified material still submerged in theoil). The wire sieve with the densified material contained therein wasthen removed from the small container and oil, and allowed to drain overthe small container for 5 minutes, except in the case of hog fuel, whichwas allowed to drain for 10 minutes. The drained wire sieve with thedensified material contained therein was weighed, and the densifiedmaterial was subsequently weighed separately. With the sieve anddensified material removed, the total weight of the small container,oil, lid and temperature probe was weighed and then the total weight ofthe small container plus oil was subsequently weighed separately.

The bone dry weight of the torrefied pellets was then calculated, andthen the bone dry weight of the pellets was compared to the loss of oil(net of evaporation of the oil) and calculated as a percentage loss ofcanola oil.

The above process was done twice for each different type of oil used(i.e., two test runs done for each different type of oil being tested),with each process starting with a 250 gram sample of densified pellets.

Results

The data from this example are shown in Table 17 and FIG. 17 for theplant-derived oils, and in Table 18 and FIG. 18 for the petroleum-basedoils. These results indicated that torrefaction of the densified biomassin the plant-derived oils generally tended to result in less oilabsorption by the resulting torrefied densified biomass, when comparedto torrefaction of the densified biomass in the petroleum-based oils.

Amongst the plant-derived oils, torrefaction of SPF pellets in sunfloweroil at 270° C. for 30 minutes resulted in the least amount of oil beingabsorbed by the densified biomass (on average about 11.38% oilabsorption). Canola oil resulted in the most oil absorption by thetorrefied densified biomass after torrefaction in canola oil at 270° C.for 30 minutes (on average about 12.12% oil absorption).

Amongst the petroleum-based oils, paraffin wax followed by 5W30 motoroil resulted in the least amount of oil absorption by the torrefieddensified biomass (on average about 16.48% and 17.10% oil absorption,respectively). Gear oil (80W90) resulted in the most oil absorption bythe torrefied densified biomass after torrefaction in the gear oil at270° C. for 30 minutes (on average about 24.32% oil absorption).

The data in Tables 17 and 18 also indicated that torrefaction inplant-derived oils resulted in a generally lower average net loss inweight of the biomass as compared to torrefaction in petroleum-basedoils. Amongst the plant-derived oils, torrefaction in peanut oilresulted in the lowest average net loss in weight (i.e., a net loss inweight of about 7.70 g) and torrefaction in sunflower oil resulted inthe highest average net loss in weight (i.e., a net loss in weight ofabout 10.85 g). Amongst the petroleum-based oils, torrefaction in barand chain oil and hydraulic fluid (AW32) resulted in the lowest averagenet losses in weight (i.e., net losses in weight of about 10.70 g and10.60 g, respectively) and torrefaction in automatic transmission fluid(ATF) resulted in the highest average net loss in weight (i.e., a netloss in weight of about 17.23 g).

As shown in Tables 17 and 18, when hog fuel was used as the startingdensified biomass, significantly greater oil absorption occurred by thehog fuel biomass in plant-derived oils (canola oil) and petroleum-basedoils (paraffin wax) and a significantly greater average net loss inweight occurred when the hog fuel biomass was torrefied in plant-derivedoils (canola oil) and petroleum-based oils (paraffin wax).

TABLE 17 Oil Absorption and Net Loss of Mass for Different Plant-derivedOils Oil Net Loss Average Oil Average Net Combustible DensifiedAbsorption in Weight Absorption Loss in Sample Liquid Biomass (%) (g)(%) Weight (g) 1 Sunflower oil SPF pellets 10.81 12.25 11.38 10.85 2Sunflower oil SPF pellets 11.96 9.45 1 Corn oil SPF pellets 11.25 9.1511.88 9.33 2 Corn oil SPF pellets 12.52 9.50 1 Peanut oil SPF pellets12.02 7.35 11.76 7.70 2 Peanut oil SPF pellets 11.50 8.05 1 Canola oilSPF pellets 10.93 12.05 12.12 10.58 2 Canola oil SPF pellets 13.30 9.101 Canola oil Hog fuel 213.40 74.00 239.27 88.23 2 Canola oil Hog fuel265.13 102.45

TABLE 18 Oil Absorption and Net Loss of Mass for DifferentPetroleum-Based Oils Oil Net Loss in Average Oil Average Net CombustibleDensified Absorption Weight Absorption Loss in Sample Liquid Biomass (%)(g) (%) Weight (g) 1 Bar and Chain oil SPF pellets 19.71 11.00 20.3910.70 2 Bar and Chain oil SPF pellets 21.07 10.40 1 5W30 motor oil SPFpellets 19.18 14.25 17.10 13.25 2 5W30 motor oil SPF pellets 15.02 12.251 Automatic SPF pellets 22.70 18.20 20.90 17.23 transmission fluid 2Automatic SPF pellets 19.10 16.25 transmission fluid 1 Hydraulic fluidSPF pellets 25.72 9.05 19.99 10.60 (AW32) 2 Hydraulic fluid SPF pellets14.26 12.15 (AW32) 1 Gear oil (80W90) SPF pellets 34.09 13.70 24.3212.93 2 Gear oil (80W90) SPF pellets 14.55 14.75 1 Paraffin wax SPFpellets 15.35 14.50 16.48 14.48 2 Paraffin wax SPF pellets 17.61 14.45 1Paraffin wax Hog fuel 230.89 73.15 231.00 65.80 2 Paraffin wax Hog fuel231.10 58.45

Example 12 Materials and Methods

In this example, 2 kilograms of densified softwood pellets made from ablend of spruce, pine and fir (SPF wood pellets) were tested. The 2kilograms were divided into 1 kilogram samples, and each 1 kilogramsample was tested using the method as described above in Example 1 in acombustible liquid (either a plant-derived oil or a petroleum-based oil)heated to a temperature of 270° C. for 30 minutes. The method wasrepeated for the 2 1-kg samples for each different type of oil.Accordingly, for each type of oil, the method was to repeated twice witha 1-kg sample each time. The resulting torrefied densified biomass fromboth test experiments for each type of oil were collected and mixedtogether to form a sample batch. One kilogram of the sample batch wascollected for testing.

In this example, the resulting 1-kg sample batch was analyzed todetermine the heat energy values of the torrefied pellets after eachtemperature-time condition.

The plant-derived oils used in this example included peanut oil,sunflower oil and corn oil. The petroleum-based oils used in thisexample included automatic transmission fluid, gear oil 80W90, motor oil(5W30), bar and chain oil, and hydraulic fluid AW32.

Results

The results shown in Tables 19 and 20 below indicated that thepetroleum-based oils generally tended to result in torrefied densifiedbiomass having slightly higher heat energy values than the densifiedbiomass that was torrefied in plant-derived oils. For example, the heatenergy values for torrefied densified biomass processed inpetroleum-based oils were approximately 26 gigajoules per metric tonne(GJ/t); whereas the heat energy values for biomass processed inplant-derived oils were approximately about 24-25 GJ/t. This differencemay be due to greater oil absorption by petroleum-processed biomass, asshown in Example 10 above.

The results further indicated that all of the plant-derived oilsproduced torrefied products with approximately similar heat energyvalues, and all of the petroleum-based oils similarly produced torrefiedproducts with approximately similar heat energy values.

TABLE 19 Heat Value of Torrefied Wood Pellets After Torrefusion at 270°C. for 30 Minutes in Plant-derived Oils Sunflower oil Corn Oil PeanutOil Wet Dry Wet Dry Wet Dry Measurements Basis Basis Basis Basis BasisBasis Weight 1 kg 1 kg 1 kg % Moisture* 1.04 0 0.78 0 1.52 0 % Ash 0.470.48 0.44 0.44 0.43 0.44 % Volatile Matter 80.96 81.81 80.69 81.32 80.2281.46 % Fixed Carbon 17.53 17.71 18.09 18.24 17.83 18.10 % Sulphur 0.020.02 0.02 0.02 0.02 0.02 Calorific Value (Gross) Btu/lb 10615 1072710616 10699 10426 10587 Kcal/kg 5897 5959 5898 5944 5792 5881 GJ/T 24.6924.95 24.69 24.89 24.25 24.62 % Carbon 58.27 58.88 58.63 59.09 57.7258.61 % Nitrogen 0.15 0.15 0.14 0.14 0.13 0.13 % Oxygen 33.34 33.6933.29 33.56 33.53 34.04 *“% Moisture” refers to the amount of water inthe samples immediately after the torrefaction process (i.e., after dripdrying for 5 minutes).

TABLE 20 Heat Value of Torrefied Wood Pellets After Torrefusion at 270°C. for 30 Minutes in Petroleum-Based Oils Automatic Bar & Chain AW32Transmission Gear Oil Motor Oil Oil Hydraulic Oil Fluid 80W90 5W30 WetDry Wet Dry Wet Dry Wet Dry Wet Dry Measurements Basis Basis Basis BasisBasis Basis Basis Basis Basis Basis Weight 1 kg 1 kg 1 kg 1 kg 1 kg %Moisture* 0.72 0 0.94 0 1.32 0 0.71 0 0.81 0 % Ash 0.44 0.45 0.57 0.570.50 0.51 0.72 0.73 0.68 0.68 % Volatile 80.00 80.58 80.14 80.90 79.9881.06 77.67 78.23 79.32 79.97 Matter % Fixed 18.84 18.97 18.35 18.5318.20 18.43 20.90 21.04 19.19 19.35 Carbon % Sulphur 0.03 0.03 0.08 0.080.04 0.04 0.13 0.13 0.04 0.04 Calorific Value (Gross) Btu/lb 10983 1106211088 11194 10951 11098 11318 11399 10892 10981 Kcal/kg 6102 6146 61606219 6084 6166 6288 6333 6051 6100 GJ/T 25.55 25.73 25.79 26.04 25.4725.81 26.33 26.51 25.33 25.54 % Carbon 59.57 60.00 60.01 60.58 59.5060.30 60.64 61.07 59.18 59.66 % Nitrogen 0.15 0.15 0.13 0.13 0.16 0.160.16 0.16 0.16 0.16 % Oxygen 32.19 32.42 31.27 31.57 31.59 32.01 30.7230.94 32.30 32.58 *“% Moisture” refers to the amount of water in thesamples immediately after the torrefaction process (i.e., after dripdrying for 5 minutes).

Example 13 Materials and Methods

A small scale torrefusion reactor was constructed in order to test thecontinuous/semi-continuous process disclosed herein. The reactorconsists of a conveyor belt that can continuously or semi-continuouslyconvey pellets through combustible liquid held in a large metal tank.The combustible liquid was heated with a temperature control. Thepellets were delivered onto the conveyor belt of the reactor, where ahopper would be located, and then conveyed along the conveyor belt into,through and then out of the combustible liquid. The reactor is shown inFIG. 19.

Results

The reactor shown in FIG. 19 was used to torrefy wood pellets anddemonstrated that a continuous/semi-continuous process could be used totorrefy pellets. Densified pellets were delivered onto the conveyor beltin hot combustible liquid (on the right-hand side of FIG. 19) andconveyed through the combustible liquid and out the other end (i.e., onthe left-hand side of FIG. 19). The pellets were fully submersed as theyconveyed along the conveyor belt through the combustible liquid and weredelivered on the other end as a torrefied densified biomass.

1. A torrefied densified biomass prepared by torrefying a densifiedbiomass feedstock in a combustible liquid, the torrefied densifiedbiomass comprising about 2% to about 25% w/w of the combustible liquid.2. The torrefied densified biomass of claim 1, wherein the combustibleliquid is a plant-derived oil.
 3. The torrefied densified biomass ofclaim 2, wherein the plant-derived oil is canola oil, linseed oil,sunflower oil, safflower oil, corn oil, peanut oil, palm oil, soybeanoil, rapeseed oil, cottonseed oil, palm kernel oil, coconut oil, sesameseed oil, olive oil, or a combination thereof.
 4. The torrefieddensified biomass of claim 1, wherein the combustible liquid is apetroleum-based oil or a bitumen-based oil.
 5. The torrefied densifiedbiomass of claim 4, wherein the petroleum-based oil or a bitumen-basedoil is a synthetic motor oil, a synthetic engine oil, a hydraulic fluid,a transmission fluid, an automatic transmission fluid, a chainsaw barand chain oil, a gear oil, a diesel fuel, a paraffin wax, or acombination thereof.
 6. The torrefied densified biomass of claim 1,wherein the densified biomass feedstock is derived from a plantmaterial.
 7. The torrefied densified biomass of claim 6, wherein theplant material is wood waste from wood-processing operations, sawdust,wood chips, straw, bagasse, waste streams from plant processingoperations, processed from crops, or a combination thereof.
 8. Thetorrefied densified biomass of claim 1, wherein the densified biomassfeedstock comprises biosolids.
 9. The torrefied densified biomass ofclaim 1, having a heat energy value of about 6,000 BTU per pound toabout 13,000 BTU per pound.
 10. The torrefied densified biomass of claim1, having a heat energy value of about 22 gigajoules per metric tonne(GJ/T) to about 27 GET on a bone dry basis.
 11. The torrefied densifiedbiomass of claim 1 having a carbon content of about 54 carbon % to about63 carbon % on a bone dry basis.
 12. A process for preparing a torrefieddensified biomass, comprising the steps of: (a) densifying a supply of abiomass feedstock to obtain a densified biomass material; (b) submergingthe densified biomass material in a combustible liquid, the combustibleliquid at a temperature between about 160° C. and about 320° C.; (c)torrefying the densified biomass material in the combustible liquid forabout 2 minutes to about 120 minutes to produce the torrefied densifiedbiomass; and (d) recovering the torrefied densified biomass; wherein thetorrefied densified biomass comprises about 2% to about 25% w/w of thecombustible liquid.
 13. A process for preparing a torrefied densifiedbiomass, comprising the steps of: (a) providing a supply of densifiedbiomass material; (b) submerging the densified biomass material in acombustible liquid, the combustible liquid at a temperature betweenabout 160° C. and about 320° C.; (c) torrefying the densified biomassmaterial in the combustible liquid for about 2 minutes to about 120minutes to produce the torrefied densified biomass; and (d) recoveringthe torrefied densified biomass; wherein the torrefied densified biomasscomprises about 2% to about 20% w/w of the combustible liquid.
 14. Aprocess for producing torrefied pellets, comprising the steps of: (a)densifying a supply of a biomass feedstock and extruding therefromdensified pellets; (b) conveying the densified pellets into and throughan input end of a torrefusion reactor; (c) submerging the densifiedpellets in a combustible liquid contained within the torrefusionreactor, the combustible liquid having a temperature between about 160°C. and about 320° C.; (d) conveying the submerged densified pellets fromthe input end to an output end of the torrefusion reactor for a periodof time from about 2 minutes to about 120 minutes, wherein the densifiedpellets are torrefied and heat and gases are produced duringtorrefaction; (e) discharging the torrefied pellets from the output endof the torrefusion reactor and conveying the torrefied pellets into andthrough a cooler; and (f) cleaning the cooled torrefied pellets toproduce cleaned torrefied pellets, the cleaned torrefied pelletscomprising about 2% to about 20% w/w of the combustible liquid.
 15. Theprocess of any of claims 12-14, wherein the supply is providedcontinuously, or semi-continuously, or in batches.
 16. The process ofclaim 14, wherein the cleaning step (f) comprises a screening process toseparate fines from the cooled torrefied pellets.
 17. The process ofclaim 14, wherein the cooler of step (e) is a water cooler and thecleaning step (f) comprises washing the cooled torrefied pellets inwater contained within the water cooler to remove residual combustibleliquid from outer surfaces of the cooled torrefied pellets.
 18. Theprocess of any of claims 12-14, further comprising the steps of: (a)combining in a torgas heater the torrefusion gases and heat producedduring torrefusion, and combusting therein to produced heated air; and(b) using the heated air to heat the combustible liquid contained withinthe torrefusion reactor.
 19. The process of claim 16, further comprisingthe steps of: (a) producing thermal energy from the separated fines; (b)combining in a torgas burner the thermal energy with the torrefusiongases and heat produced during torrefusion; (c) combusting the combinedthermal energy and torrefusion gases and heat in the torgas burner toproduce heated air; and (d) heating the combustible liquid containedwithin the torrefusion reactor using the heated air.
 20. The process ofclaim 16, wherein the wash water is used to desalinate a biomassfeedstock.